From patchwork Mon Dec 13 04:14:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12673047 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 D804BC433EF for ; Mon, 13 Dec 2021 04:15:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231609AbhLMEPk (ORCPT ); Sun, 12 Dec 2021 23:15:40 -0500 Received: from smtp-out1.suse.de ([195.135.220.28]:40580 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231604AbhLMEPj (ORCPT ); Sun, 12 Dec 2021 23:15:39 -0500 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 122D72113A; Mon, 13 Dec 2021 04:15:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1639368937; 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=XXrHRLatO4hs0zsH3aefEHCyXn58D26PMkKK/Xa88Is=; b=kc0lX2LwAeOwn77mfRrNccDpfiqR25C5+lJzjy1d8YDo1FFO/cwlVMCiEzTBRC2fOxprMg dy+kD7ZeJxBwMJH4Qn5HEPexG6UCrpFjzTLM3H7HDE+UXFCPSPFGIjjiRxbWHnO7554f7Q 3EiwHIXppRPG6Gua71Ac8tO277i4dfM= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1639368937; 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=XXrHRLatO4hs0zsH3aefEHCyXn58D26PMkKK/Xa88Is=; b=6WcTVgbYqapWhOxkTVUx4oefOQKSAkb9cp630gtNgK4raeuwV49mpGulpsB7wDJ3meXFy9 QZAocVP4m6TzgQAA== 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 6807213310; Mon, 13 Dec 2021 04:15:33 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id earBCeXItmFiPwAAMHmgww (envelope-from ); Mon, 13 Dec 2021 04:15:33 +0000 Subject: [PATCH 1/2] Remove inode_congested() From: NeilBrown To: Andrew Morton , Mel Gorman , Philipp Reisner , Lars Ellenberg , Jan Kara , Ryusuke Konishi , "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-nilfs@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Mon, 13 Dec 2021 15:14:27 +1100 Message-ID: <163936886725.23860.2403757518009677424.stgit@noble.brown> In-Reply-To: <163936868317.23860.5037433897004720387.stgit@noble.brown> References: <163936868317.23860.5037433897004720387.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. Few bdi report congestion any more, only ceph, fuse, and nfs. Have support just for them is unlikely to be useful. The places which test inode_congested() or it variants like inode_write_congested(), avoid initiation IO if congestion is present. We now have to rely on other places in the stack to back off, or abort requests - we already do for everything except these 3 filesystems. 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 67f0e88eed01..ce41d8413654 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -891,43 +891,6 @@ 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 6ae5693de28c..cc5845b8c7c3 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -595,12 +595,6 @@ void page_cache_async_ra(struct readahead_control *ractl, ClearPageReadahead(page); - /* - * 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 fb9584641ac7..540aa0ea67ff 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 @@ -1158,8 +1147,6 @@ 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; @@ -1535,9 +1522,7 @@ 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 Mon Dec 13 04:14:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12673049 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 E9E8DC4332F for ; Mon, 13 Dec 2021 04:15:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231643AbhLMEPq (ORCPT ); Sun, 12 Dec 2021 23:15:46 -0500 Received: from smtp-out1.suse.de ([195.135.220.28]:40592 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231604AbhLMEPp (ORCPT ); Sun, 12 Dec 2021 23:15:45 -0500 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 DB4B82113A; Mon, 13 Dec 2021 04:15:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1639368943; 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=mauJOVmbnPOeXWQzkrwjNtDeCONTqyDWrMEHJcDSwhI=; b=y9mEINrigUon3+6jkaj0XTJlMMg+9KMu80PGVUj+NBiSETadYXG4mK9fzQHkGUnJ5HE+WA 6UTxt/cXm/C24vDgvM2dzQBP1COhoYYgGqTodpi73MqDjm1IKk6c6YfBkqjWrr1c8hbUhg 3OOpvdPBESJuXkJer7ms/5A7tBhzfYs= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1639368943; 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=mauJOVmbnPOeXWQzkrwjNtDeCONTqyDWrMEHJcDSwhI=; b=BzUe+IcTwwx+4SrQtwSQKiXQdrZEFuOKF3a4cx6A9HKNoy/v3i6RQCgXBbQb64PcQDRyiV wnBH3qpJ5vxE9CBw== 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 3A5B213310; Mon, 13 Dec 2021 04:15:39 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id D592OuvItmFoPwAAMHmgww (envelope-from ); Mon, 13 Dec 2021 04:15:39 +0000 Subject: [PATCH 2/2] Remove bdi_congested() and wb_congested() and related functions From: NeilBrown To: Andrew Morton , Mel Gorman , Philipp Reisner , Lars Ellenberg , Jan Kara , Ryusuke Konishi , "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-nilfs@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Mon, 13 Dec 2021 15:14:27 +1100 Message-ID: <163936886727.23860.5245364396572576756.stgit@noble.brown> In-Reply-To: <163936868317.23860.5037433897004720387.stgit@noble.brown> References: <163936868317.23860.5037433897004720387.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 the only bdis that report congestion are in ceph, fuse, and nfs. None of those bdis can be the target of the calls in drbd, ext2, nilfs2, or xfs. 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. Signed-off-by: NeilBrown --- drivers/block/drbd/drbd_int.h | 3 --- drivers/block/drbd/drbd_req.c | 3 +-- fs/ext2/ialloc.c | 2 -- fs/nilfs2/segbuf.c | 11 ----------- fs/xfs/xfs_buf.c | 3 --- include/linux/backing-dev.h | 26 -------------------------- mm/vmscan.c | 4 +--- 7 files changed, 2 insertions(+), 50 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..d632764da240 100644 --- a/fs/ext2/ialloc.c +++ b/fs/ext2/ialloc.c @@ -173,8 +173,6 @@ static void ext2_preread_inode(struct inode *inode) 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..d1ebc9da7130 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); diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index 631c5a61d89b..22f73b3e888e 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 540aa0ea67ff..f46a7a17dc49 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2321,9 +2321,7 @@ 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); } /*