From patchwork Thu Feb 10 05:37:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12741285 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B4E85C43217 for ; Thu, 10 Feb 2022 05:38:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234063AbiBJFig (ORCPT ); Thu, 10 Feb 2022 00:38:36 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:35132 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233968AbiBJFie (ORCPT ); Thu, 10 Feb 2022 00:38:34 -0500 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 31FA410D6; Wed, 9 Feb 2022 21:38:30 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 807BD212BF; Thu, 10 Feb 2022 05:38:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1644471509; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=TNOQTzqXc1dwn0sxVclyo5qS7TsZyCY45jkw8WmjP7o=; b=auHoL5UkDA+g+STXd2fTFeL3cTfMH9KQgn4il9BORLboaA+LBd59sP0b5doGLioeVsK7jS NShc0YB+A9Hl8fbDJUMCdNeyKFFuCjUVWYjrf+jYzzgjFshprl/gW+8UNyMq+HxYzzky2n Df0gmTbPZ1tSdb71oNen1V3bKLmTvAs= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1644471509; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=TNOQTzqXc1dwn0sxVclyo5qS7TsZyCY45jkw8WmjP7o=; b=Kanl6OTnMHXJGXAfirc08l5F/NB5YY6FVkspt6BY1Mm/9aCVURAybuHge0yPu9tXIJs/5P A9fVQ05kFoLISgCQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id C124B13519; Thu, 10 Feb 2022 05:38:21 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id i2fSHs2kBGKsOAAAMHmgww (envelope-from ); Thu, 10 Feb 2022 05:38:21 +0000 Subject: [PATCH 01/11] DOC: convert 'subsection' to 'section' in gfp.h From: NeilBrown To: Andrew Morton , Jan Kara , Wu Fengguang , Jaegeuk Kim , Chao Yu , Jeff Layton , Ilya Dryomov , Miklos Szeredi , Trond Myklebust , Anna Schumaker , Ryusuke Konishi , "Darrick J. Wong" , Philipp Reisner , Lars Ellenberg , Paolo Valente , Jens Axboe Cc: linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-nilfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-ext4@vger.kernel.org, ceph-devel@vger.kernel.org, drbd-dev@lists.linbit.com, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Date: Thu, 10 Feb 2022 16:37:52 +1100 Message-ID: <164447147255.23354.3738954641174277133.stgit@noble.brown> In-Reply-To: <164447124918.23354.17858831070003318849.stgit@noble.brown> References: <164447124918.23354.17858831070003318849.stgit@noble.brown> User-Agent: StGit/0.23 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Various DOC: sections in gfp.h have subsection headers (~~~) but the place where they are included in mm-api.rst does not have section, only chapters. So convert to section headers (---) to avoid confusion. Specifically if section are added later in mm-api.rst, an error results. Signed-off-by: NeilBrown --- include/linux/gfp.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/include/linux/gfp.h b/include/linux/gfp.h index 80f63c862be5..20f6fbe12993 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -79,7 +79,7 @@ struct vm_area_struct; * DOC: Page mobility and placement hints * * Page mobility and placement hints - * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * --------------------------------- * * These flags provide hints about how mobile the page is. Pages with similar * mobility are placed within the same pageblocks to minimise problems due @@ -112,7 +112,7 @@ struct vm_area_struct; * DOC: Watermark modifiers * * Watermark modifiers -- controls access to emergency reserves - * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * ------------------------------------------------------------ * * %__GFP_HIGH indicates that the caller is high-priority and that granting * the request is necessary before the system can make forward progress. @@ -144,7 +144,7 @@ struct vm_area_struct; * DOC: Reclaim modifiers * * Reclaim modifiers - * ~~~~~~~~~~~~~~~~~ + * ----------------- * Please note that all the following flags are only applicable to sleepable * allocations (e.g. %GFP_NOWAIT and %GFP_ATOMIC will ignore them). * @@ -224,7 +224,7 @@ struct vm_area_struct; * DOC: Action modifiers * * Action modifiers - * ~~~~~~~~~~~~~~~~ + * ---------------- * * %__GFP_NOWARN suppresses allocation failure reports. * @@ -256,7 +256,7 @@ struct vm_area_struct; * DOC: Useful GFP flag combinations * * Useful GFP flag combinations - * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * ---------------------------- * * Useful GFP flag combinations that are commonly used. It is recommended * that subsystems start with one of these combinations and then set/clear From patchwork Thu Feb 10 05:37:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12741303 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8D6AAC4332F for ; Thu, 10 Feb 2022 05:39:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234228AbiBJFiv (ORCPT ); Thu, 10 Feb 2022 00:38:51 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:35436 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234042AbiBJFis (ORCPT ); Thu, 10 Feb 2022 00:38:48 -0500 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DD9BE10CC; Wed, 9 Feb 2022 21:38:42 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 3F43B1F43D; Thu, 10 Feb 2022 05:38:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1644471521; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=7aE0+LlADxoj0n+pYZhcga519vLh1NoOx460Fc9AvBM=; b=gjiQtnWj3gwutTC82abaAAb6TpRtme4XE3VzgJRnTJo367Csp4nU4sp/zOzMuxF2vyxuYH qBDgcUWHf9SmGXGwtBRaUd/Db06ZIsUA2pAdPV9oGRWhjgrjoIfX3WKpUWNFiS5/kOfRPg 62YIItdK6Zp4r7xUPxNHYjSo2qYyMXY= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1644471521; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=7aE0+LlADxoj0n+pYZhcga519vLh1NoOx460Fc9AvBM=; b=RO4W8dsgO64LRCac/vnEwU5jyhGcw5V+VnvGizNSElDuy7noN1dIWaybuz55SPaB/z+Gi0 rvFlNtdRVRO/jpBA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 41CC213519; Thu, 10 Feb 2022 05:38:32 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id vBtLO9ikBGK5OAAAMHmgww (envelope-from ); Thu, 10 Feb 2022 05:38:32 +0000 Subject: [PATCH 02/11] MM: document and polish read-ahead code. From: NeilBrown To: Andrew Morton , Jan Kara , Wu Fengguang , Jaegeuk Kim , Chao Yu , Jeff Layton , Ilya Dryomov , Miklos Szeredi , Trond Myklebust , Anna Schumaker , Ryusuke Konishi , "Darrick J. Wong" , Philipp Reisner , Lars Ellenberg , Paolo Valente , Jens Axboe Cc: linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-nilfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-ext4@vger.kernel.org, ceph-devel@vger.kernel.org, drbd-dev@lists.linbit.com, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Date: Thu, 10 Feb 2022 16:37:52 +1100 Message-ID: <164447147257.23354.2801426518649016278.stgit@noble.brown> In-Reply-To: <164447124918.23354.17858831070003318849.stgit@noble.brown> References: <164447124918.23354.17858831070003318849.stgit@noble.brown> User-Agent: StGit/0.23 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add some "big-picture" documentation for read-ahead and polish the code to make it fit this documentation. The meaning of ->async_size is clarified to match its name. i.e. Any request to ->readahead() has a sync part and an async part. The caller will wait for the sync pages to complete, but will not wait for the async pages. The first async page is still marked PG_readahead - in try_context_readahead(), the async_sync is set correctly rather than being set to 1. Prior to Commit 2cad40180197 ("readahead: make context readahead more conservative") it was set to ra->size which is not correct (that implies no sync component). As this was too high and caused problems it was reduced to 1, again incorrect but less problematic. The setting provided with this patch does not restore those problems, and is now not arbitrary. - The calculation of ->async_size in the initial_readahead section of ondemand_readahead() now makes sense - it is zero if the chosen size does not exceed the requested size. This means that we will not set the PG_readahead flag in this case, but as the requested size has not been satisfied we can expect a subsequent read ahead request any way. Note that the current function names page_cache_sync_ra() and page_cache_async_ra() are misleading. All ra request are partly sync and partly async, so either part can be empty. A page_cache_sync_ra() request will usually set ->async_size non-zero, implying it is not all synchronous. When a non-zero req_count is passed to page_cache_async_ra(), the implication is that some prefix of the request is synchronous, though the calculation made there is incorrect - I haven't tried to fix it. Signed-off-by: NeilBrown --- Documentation/core-api/mm-api.rst | 19 ++++++- Documentation/filesystems/vfs.rst | 16 ++++-- include/linux/fs.h | 9 +++ mm/readahead.c | 103 ++++++++++++++++++++++++++++++++++++- 4 files changed, 135 insertions(+), 12 deletions(-) diff --git a/Documentation/core-api/mm-api.rst b/Documentation/core-api/mm-api.rst index 395835f9289f..f5b2f92822c8 100644 --- a/Documentation/core-api/mm-api.rst +++ b/Documentation/core-api/mm-api.rst @@ -58,15 +58,30 @@ Virtually Contiguous Mappings File Mapping and Page Cache =========================== -.. kernel-doc:: mm/readahead.c - :export: +Filemap +------- .. kernel-doc:: mm/filemap.c :export: +Readahead +--------- + +.. kernel-doc:: mm/readahead.c + :doc: Readahead Overview + +.. kernel-doc:: mm/readahead.c + :export: + +Writeback +--------- + .. kernel-doc:: mm/page-writeback.c :export: +Truncate +-------- + .. kernel-doc:: mm/truncate.c :export: diff --git a/Documentation/filesystems/vfs.rst b/Documentation/filesystems/vfs.rst index bf5c48066fac..b4a0baa46dcc 100644 --- a/Documentation/filesystems/vfs.rst +++ b/Documentation/filesystems/vfs.rst @@ -806,12 +806,16 @@ cache in your filesystem. The following members are defined: object. The pages are consecutive in the page cache and are locked. The implementation should decrement the page refcount after starting I/O on each page. Usually the page will be - unlocked by the I/O completion handler. If the filesystem decides - to stop attempting I/O before reaching the end of the readahead - window, it can simply return. The caller will decrement the page - refcount and unlock the remaining pages for you. Set PageUptodate - if the I/O completes successfully. Setting PageError on any page - will be ignored; simply unlock the page if an I/O error occurs. + unlocked by the I/O completion handler. The set of pages are + divided into some sync pages followed by some async pages, + rac->ra->async_size gives the number of async pages. The + filesystem should attempt to read all sync pages but may decide + to stop once it reaches the async pages. If it does decide to + stop attempting I/O, it can simply return. The caller will + remove the remaining pages from the address space, unlock them + and decrement the page refcount. Set PageUptodate if the I/O + completes successfully. Setting PageError on any page will be + ignored; simply unlock the page if an I/O error occurs. ``readpages`` called by the VM to read pages associated with the address_space diff --git a/include/linux/fs.h b/include/linux/fs.h index e2d892b201b0..8b5c486bd4a2 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -930,10 +930,15 @@ struct fown_struct { * struct file_ra_state - Track a file's readahead state. * @start: Where the most recent readahead started. * @size: Number of pages read in the most recent readahead. - * @async_size: Start next readahead when this many pages are left. - * @ra_pages: Maximum size of a readahead request. + * @async_size: Numer of pages that were/are not needed immediately + * and so were/are genuinely "ahead". Start next readahead when + * the first of these pages is accessed. + * @ra_pages: Maximum size of a readahead request, copied from the bdi. * @mmap_miss: How many mmap accesses missed in the page cache. * @prev_pos: The last byte in the most recent read request. + * + * When this structure is passed to ->readahead(), the "most recent" + * readahead means the current readahead. */ struct file_ra_state { pgoff_t start; diff --git a/mm/readahead.c b/mm/readahead.c index cf0dcf89eb69..c44b2957f59f 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -8,6 +8,105 @@ * Initial version. */ +/** + * DOC: Readahead Overview + * + * Readahead is used to read content into the page cache before it is + * explicitly requested by the application. Readahead only ever + * attempts to read pages that are not yet in the page cache. If a + * page is present but not up-to-date, readahead will not try to read + * it. In that case a simple ->readpage() will be requested. + * + * Readahead is triggered when an application read request (whether a + * systemcall or a page fault) finds that the requested page is not in + * the page cache, or that it is in the page cache and has the + * %PG_readahead flag set. This flag indicates that the page was loaded + * as part of a previous read-ahead request and now that it has been + * accessed, it is time for the next read-ahead. + * + * Each readahead request is partly synchronous read, and partly async + * read-ahead. This is reflected in the struct file_ra_state which + * contains ->size being to total number of pages, and ->async_size + * which is the number of pages in the async section. The first page in + * this async section will have %PG_readahead set as a trigger for a + * subsequent read ahead. Once a series of sequential reads has been + * established, there should be no need for a synchronous component and + * all read ahead request will be fully asynchronous. + * + * When either of the triggers causes a readahead, three numbers need to + * be determined: the start of the region, the size of the region, and + * the size of the async tail. + * + * The start of the region is simply the first page address at or after + * the accessed address, which is not currently populated in the page + * cache. This is found with a simple search in the page cache. + * + * The size of the async tail is determined by subtracting the size that + * was explicitly requested from the determined request size, unless + * this would be less than zero - then zero is used. NOTE THIS + * CALCULATION IS WRONG WHEN THE START OF THE REGION IS NOT THE ACCESSED + * PAGE. + * + * The size of the region is normally determined from the size of the + * previous readahead which loaded the preceding pages. This may be + * discovered from the struct file_ra_state for simple sequential reads, + * or from examining the state of the page cache when multiple + * sequential reads are interleaved. Specifically: where the readahead + * was triggered by the %PG_readahead flag, the size of the previous + * readahead is assumed to be the number of pages from the triggering + * page to the start of the new readahead. In these cases, the size of + * the previous readahead is scaled, often doubled, for the new + * readahead, though see get_next_ra_size() for details. + * + * If the size of the previous read cannot be determined, the number of + * preceding pages in the page cache is used to estimate the size of + * a previous read. This estimate could easily be misled by random + * reads being coincidentally adjacent, so it is ignored unless it is + * larger than the current request, and it is not scaled up, unless it + * is at the start of file. + * + * In general read ahead is accelerated at the start of the file, as + * reads from there are often sequential. There are other minor + * adjustments to the read ahead size in various special cases and these + * are best discovered by reading the code. + * + * The above calculation determines the readahead, to which any requested + * read size may be added. + * + * Readahead requests are sent to the filesystem using the ->readahead() + * address space operation, for which mpage_readahead() is a canonical + * implementation. ->readahead() should normally initiate reads on all + * pages, but may fail to read any or all pages without causing an IO + * error. The page cache reading code will issue a ->readpage() request + * for any page which ->readahead() does not provided, and only an error + * from this will be final. + * + * ->readahead() will generally call readahead_page() repeatedly to get + * each page from those prepared for read ahead. It may fail to read a + * page by: + * + * * not calling readahead_page() sufficiently many times, effectively + * ignoring some pages, as might be appropriate if the path to + * storage is congested. + * + * * failing to actually submit a read request for a given page, + * possibly due to insufficient resources, or + * + * * getting an error during subsequent processing of a request. + * + * In the last two cases, the page should be unlocked to indicate that + * the read attempt has failed. In the first case the page will be + * unlocked by the caller. + * + * Those pages not in the final ``async_size`` of the request should be + * considered to be important and ->readahead() should not fail them due + * to congestion or temporary resource unavailability, but should wait + * for necessary resources (e.g. memory or indexing information) to + * become available. Pages in the final ``async_size`` may be + * considered less urgent and failure to read them is more acceptable. + * They will eventually be read individually using ->readpage(). + */ + #include #include #include @@ -426,7 +525,7 @@ static int try_context_readahead(struct address_space *mapping, ra->start = index; ra->size = min(size + req_size, max); - ra->async_size = 1; + ra->async_size = ra->size - req_size; return 1; } @@ -527,7 +626,7 @@ static void ondemand_readahead(struct readahead_control *ractl, initial_readahead: ra->start = index; ra->size = get_init_ra_size(req_size, max_pages); - ra->async_size = ra->size > req_size ? ra->size - req_size : ra->size; + ra->async_size = ra->size > req_size ? ra->size - req_size : 0; readit: /* From patchwork Thu Feb 10 05:37:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12741304 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F0331C43217 for ; Thu, 10 Feb 2022 05:39:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234360AbiBJFjR (ORCPT ); Thu, 10 Feb 2022 00:39:17 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:35508 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234243AbiBJFiw (ORCPT ); Thu, 10 Feb 2022 00:38:52 -0500 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5061D10CC; Wed, 9 Feb 2022 21:38:54 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id D576F1F43F; Thu, 10 Feb 2022 05:38:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1644471532; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Tft3SoinWu7UxepEf8WEuD+UlaGfn26eHEwniJocVAs=; b=AZtdCcwJujZVCHcdXkKOM6szi0SH98wyFfZVUIfLZbgfuKnWcUV9h+nOyBGfZYHb4fgg9q 0bzK8zlrysy2kvIK7aPM5QM5vklJlDnFMRJyEFrhh2ywPGPQAZRjcJ0eaWwg/TWCT1jT1c Y7P/mxpVQ0jyTZnT5empOfYlfVQmIKo= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1644471532; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Tft3SoinWu7UxepEf8WEuD+UlaGfn26eHEwniJocVAs=; b=yNiRicVz0d7OW6BOtosPuVbsxI1wCRGRy4fi5NKnYLY2dFaJO1i8uBQffBceecqdSDIthz JkyQL6tOSv8newBg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 4058513519; Thu, 10 Feb 2022 05:38:44 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id AC9zO+SkBGLMOAAAMHmgww (envelope-from ); Thu, 10 Feb 2022 05:38:44 +0000 Subject: [PATCH 03/11] MM: improve cleanup when ->readpages doesn't process all pages. From: NeilBrown To: Andrew Morton , Jan Kara , Wu Fengguang , Jaegeuk Kim , Chao Yu , Jeff Layton , Ilya Dryomov , Miklos Szeredi , Trond Myklebust , Anna Schumaker , Ryusuke Konishi , "Darrick J. Wong" , Philipp Reisner , Lars Ellenberg , Paolo Valente , Jens Axboe Cc: linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-nilfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-ext4@vger.kernel.org, ceph-devel@vger.kernel.org, drbd-dev@lists.linbit.com, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Date: Thu, 10 Feb 2022 16:37:52 +1100 Message-ID: <164447147258.23354.15753542879688740872.stgit@noble.brown> In-Reply-To: <164447124918.23354.17858831070003318849.stgit@noble.brown> References: <164447124918.23354.17858831070003318849.stgit@noble.brown> User-Agent: StGit/0.23 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org If ->readpages doesn't process all the pages, then it is best to act as though they weren't requested so that a subsequent readahead can try again. So: - remove any 'ahead' pages from the page cache so they can be loaded with ->readahead() rather then multiple ->read()s - update the file_ra_state to reflect the reads that were actually submitted. This allows ->readpages() to abort early due e.g. to congestion, which will then allow us to remove the inode_read_congested() test from page_Cache_async_ra(). Signed-off-by: NeilBrown --- mm/readahead.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/mm/readahead.c b/mm/readahead.c index c44b2957f59f..35a7ebfcb504 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -104,7 +104,13 @@ * for necessary resources (e.g. memory or indexing information) to * become available. Pages in the final ``async_size`` may be * considered less urgent and failure to read them is more acceptable. - * They will eventually be read individually using ->readpage(). + * In this case it is best to use delete_from_page_cache() to remove the + * pages from the page cache as is automatically done for pages that + * were not fetched with readahead_page(). This will allow a + * subsequent synchronous read ahead request to try them again. If they + * are left in the page cache, then they will be read individually using + * ->readpage(). + * */ #include @@ -226,8 +232,17 @@ static void read_pages(struct readahead_control *rac, struct list_head *pages, if (aops->readahead) { aops->readahead(rac); - /* Clean up the remaining pages */ + /* + * Clean up the remaining pages. The sizes in ->ra + * maybe be used to size next read-ahead, so make sure + * they accurately reflect what happened. + */ while ((page = readahead_page(rac))) { + rac->ra->size -= 1; + if (rac->ra->async_size > 0) { + rac->ra->async_size -= 1; + delete_from_page_cache(page); + } unlock_page(page); put_page(page); } From patchwork Thu Feb 10 05:37:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12741307 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 40387C433F5 for ; Thu, 10 Feb 2022 05:40:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234483AbiBJFk2 (ORCPT ); Thu, 10 Feb 2022 00:40:28 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:36092 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234474AbiBJFjr (ORCPT ); Thu, 10 Feb 2022 00:39:47 -0500 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D354310C7; Wed, 9 Feb 2022 21:39:20 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 8E8711F43D; Thu, 10 Feb 2022 05:39:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1644471559; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=j2iKmKfQAV47ltxyUTpJL5kF151jPpkpJZBMxZj0hPA=; b=uKgETFLiX7EG3eRXPuLaRXJzGwKmI41Y099K5XW1KSBpIkvAtu7aaGjeLAQGXG8TUQFaYO OMbK9eXz4PZqR02yAAtlGS6TlPoP/iTMR8GqWOZjaexFnysfcGLyRc7rr/3yf9JBO9+gKt oZC/hm6/xktjcHUh7EOUlnr9KfhiLHA= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1644471559; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=j2iKmKfQAV47ltxyUTpJL5kF151jPpkpJZBMxZj0hPA=; b=tFH7OafqVWs9TyFo1hmlUCp9XAM4aJZnlfF1apQOnbWq4IG7Y1nuHRPilxWK+gi9ecSy8b ySE9dRcAQmytzwCw== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 3C0FA13519; Thu, 10 Feb 2022 05:39:11 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id KeDlOv+kBGLuOAAAMHmgww (envelope-from ); Thu, 10 Feb 2022 05:39:11 +0000 Subject: [PATCH 04/11] fuse: remove reliance on bdi congestion From: NeilBrown To: Andrew Morton , Jan Kara , Wu Fengguang , Jaegeuk Kim , Chao Yu , Jeff Layton , Ilya Dryomov , Miklos Szeredi , Trond Myklebust , Anna Schumaker , Ryusuke Konishi , "Darrick J. Wong" , Philipp Reisner , Lars Ellenberg , Paolo Valente , Jens Axboe Cc: linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-nilfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-ext4@vger.kernel.org, ceph-devel@vger.kernel.org, drbd-dev@lists.linbit.com, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Date: Thu, 10 Feb 2022 16:37:52 +1100 Message-ID: <164447147258.23354.13665933242616399479.stgit@noble.brown> In-Reply-To: <164447124918.23354.17858831070003318849.stgit@noble.brown> References: <164447124918.23354.17858831070003318849.stgit@noble.brown> User-Agent: StGit/0.23 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org The bdi congestion tracking in not widely used and will be removed. Fuse is one of a small number of filesystems that uses it, setting both the sync (read) and async (write) congestion flags at what it determines are appropriate times. The only remaining effect of the sync flag is to cause read-ahead to be skipped. The only remaining effect of the async flag is to cause (some) WB_SYNC_NONE writes to be skipped. So instead of setting the flags, change: - .readahead to stop when it has submitted all non-async pages for read. - .writepages to do nothing if WB_SYNC_NONE and the flag would be set - .writepage to return AOP_WRITEPAGE_ACTIVATE if WB_SYNC_NONE and the flag would be set. The writepages change causes a behavioural change in that pageout() can now return PAGE_ACTIVATE instead of PAGE_KEEP, so SetPageActive() will be called on the page which (I think) will further delay the next attempt at writeout. This might be a good thing. Signed-off-by: NeilBrown --- fs/fuse/control.c | 17 ----------------- fs/fuse/dev.c | 8 -------- fs/fuse/file.c | 17 +++++++++++++++++ 3 files changed, 17 insertions(+), 25 deletions(-) diff --git a/fs/fuse/control.c b/fs/fuse/control.c index 000d2e5627e9..7cede9a3bc96 100644 --- a/fs/fuse/control.c +++ b/fs/fuse/control.c @@ -164,7 +164,6 @@ static ssize_t fuse_conn_congestion_threshold_write(struct file *file, { unsigned val; struct fuse_conn *fc; - struct fuse_mount *fm; ssize_t ret; ret = fuse_conn_limit_write(file, buf, count, ppos, &val, @@ -178,22 +177,6 @@ static ssize_t fuse_conn_congestion_threshold_write(struct file *file, down_read(&fc->killsb); spin_lock(&fc->bg_lock); fc->congestion_threshold = val; - - /* - * Get any fuse_mount belonging to this fuse_conn; s_bdi is - * shared between all of them - */ - - if (!list_empty(&fc->mounts)) { - fm = list_first_entry(&fc->mounts, struct fuse_mount, fc_entry); - if (fc->num_background < fc->congestion_threshold) { - clear_bdi_congested(fm->sb->s_bdi, BLK_RW_SYNC); - clear_bdi_congested(fm->sb->s_bdi, BLK_RW_ASYNC); - } else { - set_bdi_congested(fm->sb->s_bdi, BLK_RW_SYNC); - set_bdi_congested(fm->sb->s_bdi, BLK_RW_ASYNC); - } - } spin_unlock(&fc->bg_lock); up_read(&fc->killsb); fuse_conn_put(fc); diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index cd54a529460d..e1b4a846c90d 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -315,10 +315,6 @@ void fuse_request_end(struct fuse_req *req) wake_up(&fc->blocked_waitq); } - if (fc->num_background == fc->congestion_threshold && fm->sb) { - clear_bdi_congested(fm->sb->s_bdi, BLK_RW_SYNC); - clear_bdi_congested(fm->sb->s_bdi, BLK_RW_ASYNC); - } fc->num_background--; fc->active_background--; flush_bg_queue(fc); @@ -540,10 +536,6 @@ static bool fuse_request_queue_background(struct fuse_req *req) fc->num_background++; if (fc->num_background == fc->max_background) fc->blocked = 1; - if (fc->num_background == fc->congestion_threshold && fm->sb) { - set_bdi_congested(fm->sb->s_bdi, BLK_RW_SYNC); - set_bdi_congested(fm->sb->s_bdi, BLK_RW_ASYNC); - } list_add_tail(&req->list, &fc->bg_queue); flush_bg_queue(fc); queued = true; diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 829094451774..94747bac3489 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -966,6 +966,14 @@ static void fuse_readahead(struct readahead_control *rac) struct fuse_io_args *ia; struct fuse_args_pages *ap; + if (fc->num_background >= fc->congestion_threshold && + rac->ra->async_size >= readahead_count(rac)) + /* + * Congested and only async pages left, so skip the + * rest. + */ + break; + nr_pages = readahead_count(rac) - nr_pages; if (nr_pages > max_pages) nr_pages = max_pages; @@ -1958,6 +1966,7 @@ static int fuse_writepage_locked(struct page *page) static int fuse_writepage(struct page *page, struct writeback_control *wbc) { + struct fuse_conn *fc = get_fuse_conn(page->mapping->host); int err; if (fuse_page_is_writeback(page->mapping->host, page->index)) { @@ -1973,6 +1982,10 @@ static int fuse_writepage(struct page *page, struct writeback_control *wbc) return 0; } + if (wbc->sync_mode == WB_SYNC_NONE && + fc->num_background >= fc->congestion_threshold) + return AOP_WRITEPAGE_ACTIVATE; + err = fuse_writepage_locked(page); unlock_page(page); @@ -2226,6 +2239,10 @@ static int fuse_writepages(struct address_space *mapping, if (fuse_is_bad(inode)) goto out; + if (wbc->sync_mode == WB_SYNC_NONE && + fc->num_background >= fc->congestion_threshold) + return 0; + data.inode = inode; data.wpa = NULL; data.ff = NULL; From patchwork Thu Feb 10 05:37:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12741306 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD229C4321E for ; Thu, 10 Feb 2022 05:40:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234503AbiBJFkK (ORCPT ); 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Thu, 10 Feb 2022 05:39:35 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id TtwLERelBGIEOQAAMHmgww (envelope-from ); Thu, 10 Feb 2022 05:39:35 +0000 Subject: [PATCH 05/11] nfs: remove reliance on bdi congestion From: NeilBrown To: Andrew Morton , Jan Kara , Wu Fengguang , Jaegeuk Kim , Chao Yu , Jeff Layton , Ilya Dryomov , Miklos Szeredi , Trond Myklebust , Anna Schumaker , Ryusuke Konishi , "Darrick J. Wong" , Philipp Reisner , Lars Ellenberg , Paolo Valente , Jens Axboe Cc: linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-nilfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-ext4@vger.kernel.org, ceph-devel@vger.kernel.org, drbd-dev@lists.linbit.com, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Date: Thu, 10 Feb 2022 16:37:52 +1100 Message-ID: <164447147259.23354.17010890548107181818.stgit@noble.brown> In-Reply-To: <164447124918.23354.17858831070003318849.stgit@noble.brown> References: <164447124918.23354.17858831070003318849.stgit@noble.brown> User-Agent: StGit/0.23 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org The bdi congestion tracking in not widely used and will be removed. NFS is one of a small number of filesystems that uses it, setting just the async (write) congestion flag at what it determines are appropriate times. The only remaining effect of the async flag is to cause (some) WB_SYNC_NONE writes to be skipped. So instead of setting the flag, set an internal flag and change: - .writepages to do nothing if WB_SYNC_NONE and the flag is set - .writepage to return AOP_WRITEPAGE_ACTIVATE if WB_SYNC_NONE and the flag is set. The writepages change causes a behavioural change in that pageout() can now return PAGE_ACTIVATE instead of PAGE_KEEP, so SetPageActive() will be called on the page which (I think) wil further delay the next attempt at writeout. This might be a good thing. Signed-off-by: NeilBrown --- fs/nfs/write.c | 14 +++++++++++--- include/linux/nfs_fs_sb.h | 1 + 2 files changed, 12 insertions(+), 3 deletions(-) diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 987a187bd39a..7c986164018e 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -417,7 +417,7 @@ static void nfs_set_page_writeback(struct page *page) if (atomic_long_inc_return(&nfss->writeback) > NFS_CONGESTION_ON_THRESH) - set_bdi_congested(inode_to_bdi(inode), BLK_RW_ASYNC); + nfss->write_congested = 1; } static void nfs_end_page_writeback(struct nfs_page *req) @@ -433,7 +433,7 @@ static void nfs_end_page_writeback(struct nfs_page *req) end_page_writeback(req->wb_page); if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH) - clear_bdi_congested(inode_to_bdi(inode), BLK_RW_ASYNC); + nfss->write_congested = 0; } /* @@ -672,6 +672,10 @@ static int nfs_writepage_locked(struct page *page, struct inode *inode = page_file_mapping(page)->host; int err; + if (wbc->sync_mode == WB_SYNC_NONE && + NFS_SERVER(inode)->write_congested) + return AOP_WRITEPAGE_ACTIVATE; + nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE); nfs_pageio_init_write(&pgio, inode, 0, false, &nfs_async_write_completion_ops); @@ -719,6 +723,10 @@ int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc) int priority = 0; int err; + if (wbc->sync_mode == WB_SYNC_NONE && + NFS_SERVER(inode)->write_congested) + return 0; + nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES); if (!(mntflags & NFS_MOUNT_WRITE_EAGER) || wbc->for_kupdate || @@ -1893,7 +1901,7 @@ static void nfs_commit_release_pages(struct nfs_commit_data *data) } nfss = NFS_SERVER(data->inode); if (atomic_long_read(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH) - clear_bdi_congested(inode_to_bdi(data->inode), BLK_RW_ASYNC); + nfss->write_congested = 0; nfs_init_cinfo(&cinfo, data->inode, data->dreq); nfs_commit_end(cinfo.mds); diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h index ca0959e51e81..6aa2a200676a 100644 --- a/include/linux/nfs_fs_sb.h +++ b/include/linux/nfs_fs_sb.h @@ -138,6 +138,7 @@ struct nfs_server { struct nlm_host *nlm_host; /* NLM client handle */ struct nfs_iostats __percpu *io_stats; /* I/O statistics */ atomic_long_t writeback; /* number of writeback pages */ + unsigned int write_congested;/* flag set when writeback gets too high */ unsigned int flags; /* various flags */ /* The following are for internal use only. Also see uapi/linux/nfs_mount.h */ From patchwork Thu Feb 10 05:37:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12741305 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 06D27C4167B for ; Thu, 10 Feb 2022 05:40:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234582AbiBJFkL (ORCPT ); Thu, 10 Feb 2022 00:40:11 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:36612 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234431AbiBJFj7 (ORCPT ); Thu, 10 Feb 2022 00:39:59 -0500 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B64FA10C5; Wed, 9 Feb 2022 21:40:01 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 70DD91F43D; Thu, 10 Feb 2022 05:40:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1644471600; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=eBfA0J1VAN4vDciFet8kyITCSUUXphOKJM0dbNgQDlg=; b=yqtSqHyxwgEcFQ7tdufVmzaUi5fzX/LrzaAkzdhIXE5cnkTbkkI3ey9uCvPzGq0EJK8rda +E9mWICL33Dcuy7EPilwaTHUIuOW26UmS0BKCDRpVFIaT/aGIr40dAeK5kQwab4f7Y/7nd gFlh18fk9z+J+gUjbfTujF0HzFVklpA= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1644471600; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=eBfA0J1VAN4vDciFet8kyITCSUUXphOKJM0dbNgQDlg=; b=CLVBNBE0ot5kjIcVDwlr6NGjjMHQwRokAo5rn1m3cMUkvfX1d7EUuwl81RGB0IMKB7NGBI Q3kdl10ckIPVZ6Cg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 2284A13519; Thu, 10 Feb 2022 05:39:52 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id zTSyNCilBGIvOQAAMHmgww (envelope-from ); Thu, 10 Feb 2022 05:39:52 +0000 Subject: [PATCH 06/11] ceph: remove reliance on bdi congestion From: NeilBrown To: Andrew Morton , Jan Kara , Wu Fengguang , Jaegeuk Kim , Chao Yu , Jeff Layton , Ilya Dryomov , Miklos Szeredi , Trond Myklebust , Anna Schumaker , Ryusuke Konishi , "Darrick J. Wong" , Philipp Reisner , Lars Ellenberg , Paolo Valente , Jens Axboe Cc: linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-nilfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-ext4@vger.kernel.org, ceph-devel@vger.kernel.org, drbd-dev@lists.linbit.com, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Date: Thu, 10 Feb 2022 16:37:52 +1100 Message-ID: <164447147260.23354.2337728875894445797.stgit@noble.brown> In-Reply-To: <164447124918.23354.17858831070003318849.stgit@noble.brown> References: <164447124918.23354.17858831070003318849.stgit@noble.brown> User-Agent: StGit/0.23 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org The bdi congestion tracking in not widely used and will be removed. CEPHfs is one of a small number of filesystems that uses it, setting just the async (write) congestion flags at what it determines are appropriate times. The only remaining effect of the async flag is to cause (some) WB_SYNC_NONE writes to be skipped. So instead of setting the flag, set an internal flag and change: - .writepages to do nothing if WB_SYNC_NONE and the flag is set - .writepage to return AOP_WRITEPAGE_ACTIVATE if WB_SYNC_NONE and the flag is set. The writepages change causes a behavioural change in that pageout() can now return PAGE_ACTIVATE instead of PAGE_KEEP, so SetPageActive() will be called on the page which (I think) wil further delay the next attempt at writeout. This might be a good thing. Signed-off-by: NeilBrown --- fs/ceph/addr.c | 22 +++++++++++++--------- fs/ceph/super.c | 1 + fs/ceph/super.h | 1 + 3 files changed, 15 insertions(+), 9 deletions(-) diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index c98e5238a1b6..dc7af34640dd 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -563,7 +563,7 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc) if (atomic_long_inc_return(&fsc->writeback_count) > CONGESTION_ON_THRESH(fsc->mount_options->congestion_kb)) - set_bdi_congested(inode_to_bdi(inode), BLK_RW_ASYNC); + fsc->write_congested = true; req = ceph_osdc_new_request(osdc, &ci->i_layout, ceph_vino(inode), page_off, &len, 0, 1, CEPH_OSD_OP_WRITE, CEPH_OSD_FLAG_WRITE, snapc, @@ -623,7 +623,7 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc) if (atomic_long_dec_return(&fsc->writeback_count) < CONGESTION_OFF_THRESH(fsc->mount_options->congestion_kb)) - clear_bdi_congested(inode_to_bdi(inode), BLK_RW_ASYNC); + fsc->write_congested = false; return err; } @@ -635,6 +635,10 @@ static int ceph_writepage(struct page *page, struct writeback_control *wbc) BUG_ON(!inode); ihold(inode); + if (wbc->sync_mode == WB_SYNC_NONE && + ceph_inode_to_client(inode)->write_congested) + return AOP_WRITEPAGE_ACTIVATE; + wait_on_page_fscache(page); err = writepage_nounlock(page, wbc); @@ -707,8 +711,7 @@ static void writepages_finish(struct ceph_osd_request *req) if (atomic_long_dec_return(&fsc->writeback_count) < CONGESTION_OFF_THRESH( fsc->mount_options->congestion_kb)) - clear_bdi_congested(inode_to_bdi(inode), - BLK_RW_ASYNC); + fsc->write_congested = false; ceph_put_snap_context(detach_page_private(page)); end_page_writeback(page); @@ -760,6 +763,10 @@ static int ceph_writepages_start(struct address_space *mapping, bool done = false; bool caching = ceph_is_cache_enabled(inode); + if (wbc->sync_mode == WB_SYNC_NONE && + fsc->write_congested) + return 0; + dout("writepages_start %p (mode=%s)\n", inode, wbc->sync_mode == WB_SYNC_NONE ? "NONE" : (wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD")); @@ -954,11 +961,8 @@ static int ceph_writepages_start(struct address_space *mapping, if (atomic_long_inc_return(&fsc->writeback_count) > CONGESTION_ON_THRESH( - fsc->mount_options->congestion_kb)) { - set_bdi_congested(inode_to_bdi(inode), - BLK_RW_ASYNC); - } - + fsc->mount_options->congestion_kb)) + fsc->write_congested = true; pages[locked_pages++] = page; pvec.pages[i] = NULL; diff --git a/fs/ceph/super.c b/fs/ceph/super.c index bf79f369aec6..4a3b77d049c7 100644 --- a/fs/ceph/super.c +++ b/fs/ceph/super.c @@ -802,6 +802,7 @@ static struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt, fsc->have_copy_from2 = true; atomic_long_set(&fsc->writeback_count, 0); + fsc->write_congested = false; err = -ENOMEM; /* diff --git a/fs/ceph/super.h b/fs/ceph/super.h index 67f145e1ae7a..0bd97aea2319 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -121,6 +121,7 @@ struct ceph_fs_client { struct ceph_mds_client *mdsc; atomic_long_t writeback_count; + bool write_congested; struct workqueue_struct *inode_wq; struct workqueue_struct *cap_wq; From patchwork Thu Feb 10 05:37:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12741308 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D7C97C433F5 for ; Thu, 10 Feb 2022 05:40:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234704AbiBJFku (ORCPT ); Thu, 10 Feb 2022 00:40:50 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:37294 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234689AbiBJFkl (ORCPT ); Thu, 10 Feb 2022 00:40:41 -0500 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 37CF62191; Wed, 9 Feb 2022 21:40:37 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id C1113212BF; Thu, 10 Feb 2022 05:40:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1644471635; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9k0SsVBi5QRjY2tRpgnqChbWnvQSjoZJhdb/WspgxzU=; b=Yu5T3oQ4VuYeLO9DPDs3jfXJrNxmMUgbzopf1cNVoy3SV7kPKKVJWSr5QVuBsfWjZhsT/F 7lHBV1zj4w7ZmfH8+e9OoOGdViZaRInHUF6FSc0EKkh5db0hq6lSHAuSlsXsUXxPhAYRkf kIG4OSusUrrjzgs0aDcYoit2ZLXdEKM= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1644471635; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9k0SsVBi5QRjY2tRpgnqChbWnvQSjoZJhdb/WspgxzU=; b=Qk19JobDq9MGvjgEG7PbHnu5HR5EccBPnGjg4FLkcetMuh1Upe9CJLl3kCkfWzUSVStBym r71qPfjj0bj9e2DQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 3F8CF13519; Thu, 10 Feb 2022 05:40:27 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id GpIwO0ulBGJ8OQAAMHmgww (envelope-from ); Thu, 10 Feb 2022 05:40:27 +0000 Subject: [PATCH 07/11] Remove inode_congested() From: NeilBrown To: Andrew Morton , Jan Kara , Wu Fengguang , Jaegeuk Kim , Chao Yu , Jeff Layton , Ilya Dryomov , Miklos Szeredi , Trond Myklebust , Anna Schumaker , Ryusuke Konishi , "Darrick J. Wong" , Philipp Reisner , Lars Ellenberg , Paolo Valente , Jens Axboe Cc: linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-nilfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-ext4@vger.kernel.org, ceph-devel@vger.kernel.org, drbd-dev@lists.linbit.com, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Date: Thu, 10 Feb 2022 16:37:52 +1100 Message-ID: <164447147261.23354.14022902241501698367.stgit@noble.brown> In-Reply-To: <164447124918.23354.17858831070003318849.stgit@noble.brown> References: <164447124918.23354.17858831070003318849.stgit@noble.brown> User-Agent: StGit/0.23 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org inode_congested() reports if the backing-device for the inode is congested. No bdi reports congestion any more, so this always returns 'false'. So remove inode_congested() and related functions, and remove the call sites, assuming that inode_congested() always returns 'false'. Signed-off-by: NeilBrown --- fs/fs-writeback.c | 37 ------------------------------------- include/linux/backing-dev.h | 22 ---------------------- mm/fadvise.c | 5 ++--- mm/readahead.c | 6 ------ mm/vmscan.c | 17 +---------------- 5 files changed, 3 insertions(+), 84 deletions(-) diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index f8d7fe6db989..42a3dfad40b8 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -893,43 +893,6 @@ void wbc_account_cgroup_owner(struct writeback_control *wbc, struct page *page, } EXPORT_SYMBOL_GPL(wbc_account_cgroup_owner); -/** - * inode_congested - test whether an inode is congested - * @inode: inode to test for congestion (may be NULL) - * @cong_bits: mask of WB_[a]sync_congested bits to test - * - * Tests whether @inode is congested. @cong_bits is the mask of congestion - * bits to test and the return value is the mask of set bits. - * - * If cgroup writeback is enabled for @inode, the congestion state is - * determined by whether the cgwb (cgroup bdi_writeback) for the blkcg - * associated with @inode is congested; otherwise, the root wb's congestion - * state is used. - * - * @inode is allowed to be NULL as this function is often called on - * mapping->host which is NULL for the swapper space. - */ -int inode_congested(struct inode *inode, int cong_bits) -{ - /* - * Once set, ->i_wb never becomes NULL while the inode is alive. - * Start transaction iff ->i_wb is visible. - */ - if (inode && inode_to_wb_is_valid(inode)) { - struct bdi_writeback *wb; - struct wb_lock_cookie lock_cookie = {}; - bool congested; - - wb = unlocked_inode_to_wb_begin(inode, &lock_cookie); - congested = wb_congested(wb, cong_bits); - unlocked_inode_to_wb_end(inode, &lock_cookie); - return congested; - } - - return wb_congested(&inode_to_bdi(inode)->wb, cong_bits); -} -EXPORT_SYMBOL_GPL(inode_congested); - /** * wb_split_bdi_pages - split nr_pages to write according to bandwidth * @wb: target bdi_writeback to split @nr_pages to diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 483979c1b9f4..860b675c2929 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -162,7 +162,6 @@ struct bdi_writeback *wb_get_create(struct backing_dev_info *bdi, gfp_t gfp); void wb_memcg_offline(struct mem_cgroup *memcg); void wb_blkcg_offline(struct blkcg *blkcg); -int inode_congested(struct inode *inode, int cong_bits); /** * inode_cgwb_enabled - test whether cgroup writeback is enabled on an inode @@ -390,29 +389,8 @@ static inline void wb_blkcg_offline(struct blkcg *blkcg) { } -static inline int inode_congested(struct inode *inode, int cong_bits) -{ - return wb_congested(&inode_to_bdi(inode)->wb, cong_bits); -} - #endif /* CONFIG_CGROUP_WRITEBACK */ -static inline int inode_read_congested(struct inode *inode) -{ - return inode_congested(inode, 1 << WB_sync_congested); -} - -static inline int inode_write_congested(struct inode *inode) -{ - return inode_congested(inode, 1 << WB_async_congested); -} - -static inline int inode_rw_congested(struct inode *inode) -{ - return inode_congested(inode, (1 << WB_sync_congested) | - (1 << WB_async_congested)); -} - static inline int bdi_congested(struct backing_dev_info *bdi, int cong_bits) { return wb_congested(&bdi->wb, cong_bits); diff --git a/mm/fadvise.c b/mm/fadvise.c index d6baa4f451c5..338f16022012 100644 --- a/mm/fadvise.c +++ b/mm/fadvise.c @@ -109,9 +109,8 @@ int generic_fadvise(struct file *file, loff_t offset, loff_t len, int advice) case POSIX_FADV_NOREUSE: break; case POSIX_FADV_DONTNEED: - if (!inode_write_congested(mapping->host)) - __filemap_fdatawrite_range(mapping, offset, endbyte, - WB_SYNC_NONE); + __filemap_fdatawrite_range(mapping, offset, endbyte, + WB_SYNC_NONE); /* * First and last FULL page! Partial pages are deliberately diff --git a/mm/readahead.c b/mm/readahead.c index 35a7ebfcb504..31127d5f909f 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -709,12 +709,6 @@ void page_cache_async_ra(struct readahead_control *ractl, folio_clear_readahead(folio); - /* - * Defer asynchronous read-ahead on IO congestion. - */ - if (inode_read_congested(ractl->mapping->host)) - return; - if (blk_cgroup_congested()) return; diff --git a/mm/vmscan.c b/mm/vmscan.c index 090bfb605ecf..ce8492939bd3 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -989,17 +989,6 @@ static inline int is_page_cache_freeable(struct page *page) return page_count(page) - page_has_private(page) == 1 + page_cache_pins; } -static int may_write_to_inode(struct inode *inode) -{ - if (current->flags & PF_SWAPWRITE) - return 1; - if (!inode_write_congested(inode)) - return 1; - if (inode_to_bdi(inode) == current->backing_dev_info) - return 1; - return 0; -} - /* * We detected a synchronous write error writing a page out. Probably * -ENOSPC. We need to propagate that into the address_space for a subsequent @@ -1199,8 +1188,6 @@ static pageout_t pageout(struct page *page, struct address_space *mapping) } if (mapping->a_ops->writepage == NULL) return PAGE_ACTIVATE; - if (!may_write_to_inode(mapping->host)) - return PAGE_KEEP; if (clear_page_dirty_for_io(page)) { int res; @@ -1576,9 +1563,7 @@ static unsigned int shrink_page_list(struct list_head *page_list, * end of the LRU a second time. */ mapping = page_mapping(page); - if (((dirty || writeback) && mapping && - inode_write_congested(mapping->host)) || - (writeback && PageReclaim(page))) + if (writeback && PageReclaim(page)) stat->nr_congested++; /* From patchwork Thu Feb 10 05:37:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12741313 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6EE83C433EF for ; Thu, 10 Feb 2022 05:43:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234762AbiBJFnO (ORCPT ); Thu, 10 Feb 2022 00:43:14 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:37758 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234645AbiBJFl7 (ORCPT ); Thu, 10 Feb 2022 00:41:59 -0500 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3313421B2; Wed, 9 Feb 2022 21:41:07 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 3B3211F43F; Thu, 10 Feb 2022 05:41:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1644471666; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8atKcTs1vGzRKsFuuo0s3H5/aq5rfpEmJOal8XngzxM=; b=Pq3xluwCjmCg7EaeJoHMO86/e3dv2bBBRDxL1lFlfhOgh/3WF5fP8AFj7wAlyXgxoAtgMl N3+kVgBg172TD9RUqVOpd9yk2tTwTJYhBO8hlBuDzSkhgF2eE8G10va5yJGLlMVWMYDGqN xaeOuMjQy6htR+r4VtPHph4GmWGlQEI= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1644471666; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8atKcTs1vGzRKsFuuo0s3H5/aq5rfpEmJOal8XngzxM=; b=OOFNgHC24Y2xSbGzdBsWDk4om+9T3lWm/31sMpgU82LCEPPDyjRRjWMj2yoIIvnqIOGfzP iWiddXb6a4ir2ACA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id B195D13519; Thu, 10 Feb 2022 05:40:57 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id HGvqGmmlBGKbOQAAMHmgww (envelope-from ); Thu, 10 Feb 2022 05:40:57 +0000 Subject: [PATCH 08/11] Remove bdi_congested() and wb_congested() and related functions From: NeilBrown To: Andrew Morton , Jan Kara , Wu Fengguang , Jaegeuk Kim , Chao Yu , Jeff Layton , Ilya Dryomov , Miklos Szeredi , Trond Myklebust , Anna Schumaker , Ryusuke Konishi , "Darrick J. Wong" , Philipp Reisner , Lars Ellenberg , Paolo Valente , Jens Axboe Cc: linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-nilfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-ext4@vger.kernel.org, ceph-devel@vger.kernel.org, drbd-dev@lists.linbit.com, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Date: Thu, 10 Feb 2022 16:37:52 +1100 Message-ID: <164447147262.23354.13106570458589592051.stgit@noble.brown> In-Reply-To: <164447124918.23354.17858831070003318849.stgit@noble.brown> References: <164447124918.23354.17858831070003318849.stgit@noble.brown> User-Agent: StGit/0.23 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org These functions are no longer useful as no BDIs report congestions any more. Removing the test on bdi_write_contested() in current_may_throttle() could cause a small change in behaviour, but only when PF_LOCAL_THROTTLE is set. So replace the calls by 'false' and simplify the code - and remove the functions. Acked-by: Ryusuke Konishi (for nilfs bits) Signed-off-by: NeilBrown --- drivers/block/drbd/drbd_int.h | 3 --- drivers/block/drbd/drbd_req.c | 3 +-- fs/ext2/ialloc.c | 5 ----- fs/nilfs2/segbuf.c | 15 --------------- fs/xfs/xfs_buf.c | 3 --- include/linux/backing-dev.h | 26 -------------------------- mm/vmscan.c | 4 +--- 7 files changed, 2 insertions(+), 57 deletions(-) diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h index f27d5b0f9a0b..f804b1bfb3e6 100644 --- a/drivers/block/drbd/drbd_int.h +++ b/drivers/block/drbd/drbd_int.h @@ -638,9 +638,6 @@ enum { STATE_SENT, /* Do not change state/UUIDs while this is set */ CALLBACK_PENDING, /* Whether we have a call_usermodehelper(, UMH_WAIT_PROC) * pending, from drbd worker context. - * If set, bdi_write_congested() returns true, - * so shrink_page_list() would not recurse into, - * and potentially deadlock on, this drbd worker. */ DISCONNECT_SENT, diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index 3235532ae077..2e5fb7e442e3 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -909,8 +909,7 @@ static bool remote_due_to_read_balancing(struct drbd_device *device, sector_t se switch (rbm) { case RB_CONGESTED_REMOTE: - return bdi_read_congested( - device->ldev->backing_bdev->bd_disk->bdi); + return 0; case RB_LEAST_PENDING: return atomic_read(&device->local_cnt) > atomic_read(&device->ap_pending_cnt) + atomic_read(&device->rs_pending_cnt); diff --git a/fs/ext2/ialloc.c b/fs/ext2/ialloc.c index df14e750e9fe..998dd2ac8008 100644 --- a/fs/ext2/ialloc.c +++ b/fs/ext2/ialloc.c @@ -170,11 +170,6 @@ static void ext2_preread_inode(struct inode *inode) unsigned long offset; unsigned long block; struct ext2_group_desc * gdp; - struct backing_dev_info *bdi; - - bdi = inode_to_bdi(inode); - if (bdi_rw_congested(bdi)) - return; block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); gdp = ext2_get_group_desc(inode->i_sb, block_group, NULL); diff --git a/fs/nilfs2/segbuf.c b/fs/nilfs2/segbuf.c index 43287b0d3e9b..c4510f79037f 100644 --- a/fs/nilfs2/segbuf.c +++ b/fs/nilfs2/segbuf.c @@ -343,17 +343,6 @@ static int nilfs_segbuf_submit_bio(struct nilfs_segment_buffer *segbuf, struct bio *bio = wi->bio; int err; - if (segbuf->sb_nbio > 0 && - bdi_write_congested(segbuf->sb_super->s_bdi)) { - wait_for_completion(&segbuf->sb_bio_event); - segbuf->sb_nbio--; - if (unlikely(atomic_read(&segbuf->sb_err))) { - bio_put(bio); - err = -EIO; - goto failed; - } - } - bio->bi_end_io = nilfs_end_bio_write; bio->bi_private = segbuf; bio_set_op_attrs(bio, mode, mode_flags); @@ -365,10 +354,6 @@ static int nilfs_segbuf_submit_bio(struct nilfs_segment_buffer *segbuf, wi->nr_vecs = min(wi->max_pages, wi->rest_blocks); wi->start = wi->end; return 0; - - failed: - wi->bio = NULL; - return err; } /** diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index b45e0d50a405..b7ebcfe6b8d3 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -843,9 +843,6 @@ xfs_buf_readahead_map( { struct xfs_buf *bp; - if (bdi_read_congested(target->bt_bdev->bd_disk->bdi)) - return; - xfs_buf_read_map(target, map, nmaps, XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD, &bp, ops, __this_address); diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 860b675c2929..2d764566280c 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -135,11 +135,6 @@ static inline bool writeback_in_progress(struct bdi_writeback *wb) struct backing_dev_info *inode_to_bdi(struct inode *inode); -static inline int wb_congested(struct bdi_writeback *wb, int cong_bits) -{ - return wb->congested & cong_bits; -} - long congestion_wait(int sync, long timeout); static inline bool mapping_can_writeback(struct address_space *mapping) @@ -391,27 +386,6 @@ static inline void wb_blkcg_offline(struct blkcg *blkcg) #endif /* CONFIG_CGROUP_WRITEBACK */ -static inline int bdi_congested(struct backing_dev_info *bdi, int cong_bits) -{ - return wb_congested(&bdi->wb, cong_bits); -} - -static inline int bdi_read_congested(struct backing_dev_info *bdi) -{ - return bdi_congested(bdi, 1 << WB_sync_congested); -} - -static inline int bdi_write_congested(struct backing_dev_info *bdi) -{ - return bdi_congested(bdi, 1 << WB_async_congested); -} - -static inline int bdi_rw_congested(struct backing_dev_info *bdi) -{ - return bdi_congested(bdi, (1 << WB_sync_congested) | - (1 << WB_async_congested)); -} - const char *bdi_dev_name(struct backing_dev_info *bdi); #endif /* _LINUX_BACKING_DEV_H */ diff --git a/mm/vmscan.c b/mm/vmscan.c index ce8492939bd3..0b930556c4f2 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2362,9 +2362,7 @@ static unsigned int move_pages_to_lru(struct lruvec *lruvec, */ static int current_may_throttle(void) { - return !(current->flags & PF_LOCAL_THROTTLE) || - current->backing_dev_info == NULL || - bdi_write_congested(current->backing_dev_info); + return !(current->flags & PF_LOCAL_THROTTLE); } /* From patchwork Thu Feb 10 05:37:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12741312 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B6CBC433EF for ; Thu, 10 Feb 2022 05:43:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234354AbiBJFmt (ORCPT ); Thu, 10 Feb 2022 00:42:49 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:37282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234248AbiBJFmU (ORCPT ); Thu, 10 Feb 2022 00:42:20 -0500 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1798D2605; 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t=1644471685; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=QxH/65m79qvzBGSCwVr/N2GJs7ZD/rte4Udz5IqpfIY=; b=6n0i9ic8w1i2aZJ9N2rX+fVNb4ZqLqNFRFiTjK1N/idKrQahO5XYfaUQ4n8fWkZ2pi7f30 fq+mOgq70ftta4BQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 0457313519; Thu, 10 Feb 2022 05:41:17 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id z0pPLH2lBGKxOQAAMHmgww (envelope-from ); Thu, 10 Feb 2022 05:41:17 +0000 Subject: [PATCH 09/11] f2fs: replace congestion_wait() calls with io_schedule_timeout() From: NeilBrown To: Andrew Morton , Jan Kara , Wu Fengguang , Jaegeuk Kim , Chao Yu , Jeff Layton , Ilya Dryomov , Miklos Szeredi , Trond Myklebust , Anna Schumaker , Ryusuke Konishi , "Darrick J. Wong" , Philipp Reisner , Lars Ellenberg , Paolo Valente , Jens Axboe Cc: linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-nilfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-ext4@vger.kernel.org, ceph-devel@vger.kernel.org, drbd-dev@lists.linbit.com, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Date: Thu, 10 Feb 2022 16:37:52 +1100 Message-ID: <164447147263.23354.4653093481289339536.stgit@noble.brown> In-Reply-To: <164447124918.23354.17858831070003318849.stgit@noble.brown> References: <164447124918.23354.17858831070003318849.stgit@noble.brown> User-Agent: StGit/0.23 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org As congestion is no longer tracked, congestion_wait() is effectively equivalent to io_schedule_timeout(). So introduce f2fs_io_schedule_timeout() which sets TASK_UNINTERRUPTIBLE and call that instead. Signed-off-by: NeilBrown --- fs/f2fs/compress.c | 4 +--- fs/f2fs/data.c | 3 +-- fs/f2fs/f2fs.h | 6 ++++++ fs/f2fs/segment.c | 8 +++----- fs/f2fs/super.c | 6 ++---- 5 files changed, 13 insertions(+), 14 deletions(-) diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c index d0c3aeba5945..2f95559025ad 100644 --- a/fs/f2fs/compress.c +++ b/fs/f2fs/compress.c @@ -1505,9 +1505,7 @@ static int f2fs_write_raw_pages(struct compress_ctx *cc, if (IS_NOQUOTA(cc->inode)) return 0; ret = 0; - cond_resched(); - congestion_wait(BLK_RW_ASYNC, - DEFAULT_IO_TIMEOUT); + f2fs_io_schedule_timeout(DEFAULT_IO_TIMEOUT); goto retry_write; } return ret; diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 8c417864c66a..d428ddfd42ee 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -3047,8 +3047,7 @@ static int f2fs_write_cache_pages(struct address_space *mapping, } else if (ret == -EAGAIN) { ret = 0; if (wbc->sync_mode == WB_SYNC_ALL) { - cond_resched(); - congestion_wait(BLK_RW_ASYNC, + f2fs_io_schedule_timeout( DEFAULT_IO_TIMEOUT); goto retry_write; } diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 68b44015514f..467f5dbdc7d1 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -4426,6 +4426,12 @@ static inline bool f2fs_block_unit_discard(struct f2fs_sb_info *sbi) return F2FS_OPTION(sbi).discard_unit == DISCARD_UNIT_BLOCK; } +static inline void f2fs_io_schedule_timeout(long timeout) +{ + set_current_state(TASK_UNINTERRUPTIBLE); + io_schedule_timeout(timeout); +} + #define EFSBADCRC EBADMSG /* Bad CRC detected */ #define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */ diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 1dabc8244083..6ff20da44ad7 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -313,8 +313,7 @@ void f2fs_drop_inmem_pages_all(struct f2fs_sb_info *sbi, bool gc_failure) skip: iput(inode); } - congestion_wait(BLK_RW_ASYNC, DEFAULT_IO_TIMEOUT); - cond_resched(); + f2fs_io_schedule_timeout(DEFAULT_IO_TIMEOUT); if (gc_failure) { if (++looped >= count) return; @@ -803,8 +802,7 @@ int f2fs_flush_device_cache(struct f2fs_sb_info *sbi) do { ret = __submit_flush_wait(sbi, FDEV(i).bdev); if (ret) - congestion_wait(BLK_RW_ASYNC, - DEFAULT_IO_TIMEOUT); + f2fs_io_schedule_timeout(DEFAULT_IO_TIMEOUT); } while (ret && --count); if (ret) { @@ -3133,7 +3131,7 @@ static unsigned int __issue_discard_cmd_range(struct f2fs_sb_info *sbi, blk_finish_plug(&plug); mutex_unlock(&dcc->cmd_lock); trimmed += __wait_all_discard_cmd(sbi, NULL); - congestion_wait(BLK_RW_ASYNC, DEFAULT_IO_TIMEOUT); + f2fs_io_schedule_timeout(DEFAULT_IO_TIMEOUT); goto next; } skip: diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index baefd398ec1a..ebd32daf052c 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -2135,8 +2135,7 @@ static void f2fs_enable_checkpoint(struct f2fs_sb_info *sbi) /* we should flush all the data to keep data consistency */ do { sync_inodes_sb(sbi->sb); - cond_resched(); - congestion_wait(BLK_RW_ASYNC, DEFAULT_IO_TIMEOUT); + f2fs_io_schedule_timeout(DEFAULT_IO_TIMEOUT); } while (get_pages(sbi, F2FS_DIRTY_DATA) && retry--); if (unlikely(retry < 0)) @@ -2504,8 +2503,7 @@ static ssize_t f2fs_quota_write(struct super_block *sb, int type, &page, &fsdata); if (unlikely(err)) { if (err == -ENOMEM) { - congestion_wait(BLK_RW_ASYNC, - DEFAULT_IO_TIMEOUT); + f2fs_io_schedule_timeout(DEFAULT_IO_TIMEOUT); goto retry; } set_sbi_flag(F2FS_SB(sb), SBI_QUOTA_NEED_REPAIR); From patchwork Thu Feb 10 05:37:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12741311 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A34CDC433EF for ; Thu, 10 Feb 2022 05:42:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233652AbiBJFml (ORCPT ); Thu, 10 Feb 2022 00:42:41 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:38538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234390AbiBJFmX (ORCPT ); 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Wong" , Philipp Reisner , Lars Ellenberg , Paolo Valente , Jens Axboe Cc: linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-nilfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-ext4@vger.kernel.org, ceph-devel@vger.kernel.org, drbd-dev@lists.linbit.com, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Date: Thu, 10 Feb 2022 16:37:52 +1100 Message-ID: <164447147264.23354.2763356897218946255.stgit@noble.brown> In-Reply-To: <164447124918.23354.17858831070003318849.stgit@noble.brown> References: <164447124918.23354.17858831070003318849.stgit@noble.brown> User-Agent: StGit/0.23 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org bfq_get_queue() expects a "bool" for the third arg, so pass "false" rather than "BLK_RW_ASYNC" which will soon be removed. Acked-by: Jens Axboe Signed-off-by: NeilBrown Reviewed-by: Jan Kara --- block/bfq-iosched.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 0c612a911696..4e645ae1e066 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -5448,7 +5448,7 @@ static void bfq_check_ioprio_change(struct bfq_io_cq *bic, struct bio *bio) bfqq = bic_to_bfqq(bic, false); if (bfqq) { bfq_release_process_ref(bfqd, bfqq); - bfqq = bfq_get_queue(bfqd, bio, BLK_RW_ASYNC, bic, true); + bfqq = bfq_get_queue(bfqd, bio, false, bic, true); bic_set_bfqq(bic, bfqq, false); } From patchwork Thu Feb 10 05:37:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12741310 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0A47BC43217 for ; Thu, 10 Feb 2022 05:42:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234616AbiBJFmi (ORCPT ); Thu, 10 Feb 2022 00:42:38 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:37636 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234503AbiBJFmY (ORCPT ); Thu, 10 Feb 2022 00:42:24 -0500 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B797B10F1; Wed, 9 Feb 2022 21:42:15 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 734731F43D; Thu, 10 Feb 2022 05:42:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1644471734; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=OVO5L5oh76QqfW3n1oDvBos2Yawv0E43OsrqMmz97u8=; b=Y4cUvv3PJKyVMz8FNNEhmRww+IPf1vCeOOqK0FTWuDkeqM36XCK+AT8cYSkRQj3MZKfu3r v/b3UW0dtqYI7tKPjKNqQmlmd3jV8sqKw4tyRVLHUsEkdFKTms2Z28azua5ApNmWzRTxoH UsC2mc1GYUclXUtzq8DpUDJ3JGzRa+g= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1644471734; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=OVO5L5oh76QqfW3n1oDvBos2Yawv0E43OsrqMmz97u8=; b=ZPiYBWU/AizPDshG554+eG+xjMBZbCVDQCLFKr1TUieBkKh7aijrZhoVE1LxpUkABVYzre zW6kHS8R6+LYlmBg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id BDE7213519; Thu, 10 Feb 2022 05:42:06 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 7KNxHq6lBGLoOQAAMHmgww (envelope-from ); Thu, 10 Feb 2022 05:42:06 +0000 Subject: [PATCH 11/11] Remove congestion tracking framework. From: NeilBrown To: Andrew Morton , Jan Kara , Wu Fengguang , Jaegeuk Kim , Chao Yu , Jeff Layton , Ilya Dryomov , Miklos Szeredi , Trond Myklebust , Anna Schumaker , Ryusuke Konishi , "Darrick J. Wong" , Philipp Reisner , Lars Ellenberg , Paolo Valente , Jens Axboe Cc: linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-nilfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-ext4@vger.kernel.org, ceph-devel@vger.kernel.org, drbd-dev@lists.linbit.com, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Date: Thu, 10 Feb 2022 16:37:52 +1100 Message-ID: <164447147265.23354.13590371223377061333.stgit@noble.brown> In-Reply-To: <164447124918.23354.17858831070003318849.stgit@noble.brown> References: <164447124918.23354.17858831070003318849.stgit@noble.brown> User-Agent: StGit/0.23 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org This framework is no longer used - so discard it. Signed-off-by: NeilBrown --- include/linux/backing-dev-defs.h | 8 ----- include/linux/backing-dev.h | 2 - include/trace/events/writeback.h | 28 ------------------- mm/backing-dev.c | 57 -------------------------------------- 4 files changed, 95 deletions(-) diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h index 993c5628a726..e863c88df95f 100644 --- a/include/linux/backing-dev-defs.h +++ b/include/linux/backing-dev-defs.h @@ -207,14 +207,6 @@ struct backing_dev_info { #endif }; -enum { - BLK_RW_ASYNC = 0, - BLK_RW_SYNC = 1, -}; - -void clear_bdi_congested(struct backing_dev_info *bdi, int sync); -void set_bdi_congested(struct backing_dev_info *bdi, int sync); - struct wb_lock_cookie { bool locked; unsigned long flags; diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 2d764566280c..87ce24d238f3 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -135,8 +135,6 @@ static inline bool writeback_in_progress(struct bdi_writeback *wb) struct backing_dev_info *inode_to_bdi(struct inode *inode); -long congestion_wait(int sync, long timeout); - static inline bool mapping_can_writeback(struct address_space *mapping) { return inode_to_bdi(mapping->host)->capabilities & BDI_CAP_WRITEBACK; diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h index a345b1e12daf..86b2a82da546 100644 --- a/include/trace/events/writeback.h +++ b/include/trace/events/writeback.h @@ -735,34 +735,6 @@ TRACE_EVENT(writeback_sb_inodes_requeue, ) ); -DECLARE_EVENT_CLASS(writeback_congest_waited_template, - - TP_PROTO(unsigned int usec_timeout, unsigned int usec_delayed), - - TP_ARGS(usec_timeout, usec_delayed), - - TP_STRUCT__entry( - __field( unsigned int, usec_timeout ) - __field( unsigned int, usec_delayed ) - ), - - TP_fast_assign( - __entry->usec_timeout = usec_timeout; - __entry->usec_delayed = usec_delayed; - ), - - TP_printk("usec_timeout=%u usec_delayed=%u", - __entry->usec_timeout, - __entry->usec_delayed) -); - -DEFINE_EVENT(writeback_congest_waited_template, writeback_congestion_wait, - - TP_PROTO(unsigned int usec_timeout, unsigned int usec_delayed), - - TP_ARGS(usec_timeout, usec_delayed) -); - DECLARE_EVENT_CLASS(writeback_single_inode_template, TP_PROTO(struct inode *inode, diff --git a/mm/backing-dev.c b/mm/backing-dev.c index eae96dfe0261..7176af65b103 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -1005,60 +1005,3 @@ const char *bdi_dev_name(struct backing_dev_info *bdi) return bdi->dev_name; } EXPORT_SYMBOL_GPL(bdi_dev_name); - -static wait_queue_head_t congestion_wqh[2] = { - __WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[0]), - __WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[1]) - }; -static atomic_t nr_wb_congested[2]; - -void clear_bdi_congested(struct backing_dev_info *bdi, int sync) -{ - wait_queue_head_t *wqh = &congestion_wqh[sync]; - enum wb_congested_state bit; - - bit = sync ? WB_sync_congested : WB_async_congested; - if (test_and_clear_bit(bit, &bdi->wb.congested)) - atomic_dec(&nr_wb_congested[sync]); - smp_mb__after_atomic(); - if (waitqueue_active(wqh)) - wake_up(wqh); -} -EXPORT_SYMBOL(clear_bdi_congested); - -void set_bdi_congested(struct backing_dev_info *bdi, int sync) -{ - enum wb_congested_state bit; - - bit = sync ? WB_sync_congested : WB_async_congested; - if (!test_and_set_bit(bit, &bdi->wb.congested)) - atomic_inc(&nr_wb_congested[sync]); -} -EXPORT_SYMBOL(set_bdi_congested); - -/** - * congestion_wait - wait for a backing_dev to become uncongested - * @sync: SYNC or ASYNC IO - * @timeout: timeout in jiffies - * - * Waits for up to @timeout jiffies for a backing_dev (any backing_dev) to exit - * write congestion. If no backing_devs are congested then just wait for the - * next write to be completed. - */ -long congestion_wait(int sync, long timeout) -{ - long ret; - unsigned long start = jiffies; - DEFINE_WAIT(wait); - wait_queue_head_t *wqh = &congestion_wqh[sync]; - - prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE); - ret = io_schedule_timeout(timeout); - finish_wait(wqh, &wait); - - trace_writeback_congestion_wait(jiffies_to_usecs(timeout), - jiffies_to_usecs(jiffies - start)); - - return ret; -} -EXPORT_SYMBOL(congestion_wait);