From patchwork Mon Jul 15 09:44:50 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Pankaj Raghav (Samsung)" X-Patchwork-Id: 13733196 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 810DDC3DA59 for ; Mon, 15 Jul 2024 09:45:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 135B36B0096; Mon, 15 Jul 2024 05:45:30 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0BF466B0098; Mon, 15 Jul 2024 05:45:30 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E79B36B0099; Mon, 15 Jul 2024 05:45:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id C702E6B0096 for ; Mon, 15 Jul 2024 05:45:29 -0400 (EDT) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 21E9B812A0 for ; Mon, 15 Jul 2024 09:45:29 +0000 (UTC) X-FDA: 82341504378.08.B4DDB62 Received: from mout-p-201.mailbox.org (mout-p-201.mailbox.org [80.241.56.171]) by imf04.hostedemail.com (Postfix) with ESMTP id 50EAF40002 for ; Mon, 15 Jul 2024 09:45:27 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=pankajraghav.com header.s=MBO0001 header.b=MPzv2L2c; spf=pass (imf04.hostedemail.com: domain of kernel@pankajraghav.com designates 80.241.56.171 as permitted sender) smtp.mailfrom=kernel@pankajraghav.com; dmarc=pass (policy=quarantine) header.from=pankajraghav.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1721036709; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=+r0q1aMOVXTo8fjQ8nnAWfzQgFhULOwQhra2cgoZxE8=; b=f/LlwjewZ2rsejw5k2PFyF3QkzpHS244p0bNpgNQbHUcD5mati5yLAIwi7W+ezTxDiTNq0 A9vHHzYD3UfMk6ilTvD6tvzvCEsl5IdiKtuX48pB+cQB1R7kIRS9rEM1Mprv352AdUCOd8 HyKJhiXTGanh7/VBnzhEKtunsYxgiJ4= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=pass header.d=pankajraghav.com header.s=MBO0001 header.b=MPzv2L2c; spf=pass (imf04.hostedemail.com: domain of kernel@pankajraghav.com designates 80.241.56.171 as permitted sender) smtp.mailfrom=kernel@pankajraghav.com; dmarc=pass (policy=quarantine) header.from=pankajraghav.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1721036709; a=rsa-sha256; cv=none; b=M4wk0ViZj0oCv+qub7PPu7oA/Cejs5tSUSd41uVqjeMaobeMMKWJE9OBs8irVyH0XkzJdm i1ddl1Ur/Um/3XkOVlXO9OlfkDCXKC261MPH8NUT/UD+gHVlmSnMZTuVVHIBzIsUnWlfZt /e02r+vKUXcWo3OvYpDejYOJ+OsoOjs= Received: from smtp1.mailbox.org (smtp1.mailbox.org [IPv6:2001:67c:2050:b231:465::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-201.mailbox.org (Postfix) with ESMTPS id 4WMy440n14z9sTZ; Mon, 15 Jul 2024 11:45:24 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pankajraghav.com; s=MBO0001; t=1721036724; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+r0q1aMOVXTo8fjQ8nnAWfzQgFhULOwQhra2cgoZxE8=; b=MPzv2L2cbA7bhRj+HBdFq7IV5GhVXEzrexjnJkSoPIfhP2GEZGuhXxyhEOe0Ms7y/ocywO L8K4TcQWxWuJQUtPJF8f4gQixz+ygHJ+Pc1fsSWAukfyFfxGFEhVd9kt7hQCCTj14EewnK 4KpZMXbpnaUcPM47K6StBjFZIytFf8y6EtakBuEYUZsm5rJwDniWRAfGYc+A/qdWdm/EBS XTmkLr+RHuetG5Hl7nlqoaXIqnBws83vgzpcrTsDX58GkUHqpYl0EEmhN3y+WKxQzLsncY iB561MZ2QwASg5TVPrMXiO2VbVZ56Ujygc4zRbBuOgyK4xKw4RKnnld+tJT7Aw== From: "Pankaj Raghav (Samsung)" To: david@fromorbit.com, willy@infradead.org, chandan.babu@oracle.com, djwong@kernel.org, brauner@kernel.org, akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, yang@os.amperecomputing.com, linux-mm@kvack.org, john.g.garry@oracle.com, linux-fsdevel@vger.kernel.org, hare@suse.de, p.raghav@samsung.com, mcgrof@kernel.org, gost.dev@samsung.com, cl@os.amperecomputing.com, linux-xfs@vger.kernel.org, kernel@pankajraghav.com, ryan.roberts@arm.com, hch@lst.de, Zi Yan Subject: [PATCH v10 03/10] readahead: allocate folios with mapping_min_order in readahead Date: Mon, 15 Jul 2024 11:44:50 +0200 Message-ID: <20240715094457.452836-4-kernel@pankajraghav.com> In-Reply-To: <20240715094457.452836-1-kernel@pankajraghav.com> References: <20240715094457.452836-1-kernel@pankajraghav.com> MIME-Version: 1.0 X-Rspamd-Server: rspam03 X-Rspam-User: X-Rspamd-Queue-Id: 50EAF40002 X-Stat-Signature: d4p5uppzbxziqj6mineugukoo8j9kxiq X-HE-Tag: 1721036727-886059 X-HE-Meta: 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 +KETN4p6 BVY7pxdbGYLQOeMU7XmZLCZE2sMAhLATve6yihY0YmblTxaoA2NqlubsbyISO4vjSWNAeTJWeTNH46XfxoBsckYRnWxaEkFnSklrGTKL5w/nfcauaYPZ87E0ztUlT8KL64o/acSNcws7fesl3HW+s4yvpPBPdCDD5p7SOYd40PwoyZKB1pePFueCxwP/GtAnpwEsehXZTfLfwmMyyRT5iJE3wVQSXgzMzOY7+YWsN6om2ijxxzhLAMFbpD8L7yBTUFFbztb3unyiUq3KxXXVnJuCmhWwNY1hV456brAcOIHwnkeszaNdvDSV253faOE/HEoYtThlzemZGkBRPr5zdfeKTvYFcnhGT3IYuwQ7/N6he/FVgIEpfELh9Dw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Pankaj Raghav page_cache_ra_unbounded() was allocating single pages (0 order folios) if there was no folio found in an index. Allocate mapping_min_order folios as we need to guarantee the minimum order if it is set. page_cache_ra_order() tries to allocate folio to the page cache with a higher order if the index aligns with that order. Modify it so that the order does not go below the mapping_min_order requirement of the page cache. This function will do the right thing even if the new_order passed is less than the mapping_min_order. When adding new folios to the page cache we must also ensure the index used is aligned to the mapping_min_order as the page cache requires the index to be aligned to the order of the folio. readahead_expand() is called from readahead aops to extend the range of the readahead so this function can assume ractl->_index to be aligned with min_order. Signed-off-by: Pankaj Raghav Co-developed-by: Hannes Reinecke Signed-off-by: Hannes Reinecke Acked-by: Darrick J. Wong --- mm/readahead.c | 79 ++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 61 insertions(+), 18 deletions(-) diff --git a/mm/readahead.c b/mm/readahead.c index 3e5239e9e1777..2078c42777a62 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -206,9 +206,10 @@ void page_cache_ra_unbounded(struct readahead_control *ractl, unsigned long nr_to_read, unsigned long lookahead_size) { struct address_space *mapping = ractl->mapping; - unsigned long index = readahead_index(ractl); + unsigned long ra_folio_index, index = readahead_index(ractl); gfp_t gfp_mask = readahead_gfp_mask(mapping); - unsigned long i; + unsigned long mark, i = 0; + unsigned int min_nrpages = mapping_min_folio_nrpages(mapping); /* * Partway through the readahead operation, we will have added @@ -223,10 +224,24 @@ void page_cache_ra_unbounded(struct readahead_control *ractl, unsigned int nofs = memalloc_nofs_save(); filemap_invalidate_lock_shared(mapping); + index = mapping_align_index(mapping, index); + + /* + * As iterator `i` is aligned to min_nrpages, round_up the + * difference between nr_to_read and lookahead_size to mark the + * index that only has lookahead or "async_region" to set the + * readahead flag. + */ + ra_folio_index = round_up(readahead_index(ractl) + nr_to_read - lookahead_size, + min_nrpages); + mark = ra_folio_index - index; + nr_to_read += readahead_index(ractl) - index; + ractl->_index = index; + /* * Preallocate as many pages as we will need. */ - for (i = 0; i < nr_to_read; i++) { + while (i < nr_to_read) { struct folio *folio = xa_load(&mapping->i_pages, index + i); int ret; @@ -240,12 +255,13 @@ void page_cache_ra_unbounded(struct readahead_control *ractl, * not worth getting one just for that. */ read_pages(ractl); - ractl->_index++; - i = ractl->_index + ractl->_nr_pages - index - 1; + ractl->_index += min_nrpages; + i = ractl->_index + ractl->_nr_pages - index; continue; } - folio = filemap_alloc_folio(gfp_mask, 0); + folio = filemap_alloc_folio(gfp_mask, + mapping_min_folio_order(mapping)); if (!folio) break; @@ -255,14 +271,15 @@ void page_cache_ra_unbounded(struct readahead_control *ractl, if (ret == -ENOMEM) break; read_pages(ractl); - ractl->_index++; - i = ractl->_index + ractl->_nr_pages - index - 1; + ractl->_index += min_nrpages; + i = ractl->_index + ractl->_nr_pages - index; continue; } - if (i == nr_to_read - lookahead_size) + if (i == mark) folio_set_readahead(folio); ractl->_workingset |= folio_test_workingset(folio); - ractl->_nr_pages++; + ractl->_nr_pages += min_nrpages; + i += min_nrpages; } /* @@ -438,13 +455,19 @@ void page_cache_ra_order(struct readahead_control *ractl, struct address_space *mapping = ractl->mapping; pgoff_t start = readahead_index(ractl); pgoff_t index = start; + unsigned int min_order = mapping_min_folio_order(mapping); pgoff_t limit = (i_size_read(mapping->host) - 1) >> PAGE_SHIFT; pgoff_t mark = index + ra->size - ra->async_size; unsigned int nofs; int err = 0; gfp_t gfp = readahead_gfp_mask(mapping); + unsigned int min_ra_size = max(4, mapping_min_folio_nrpages(mapping)); - if (!mapping_large_folio_support(mapping) || ra->size < 4) + /* + * Fallback when size < min_nrpages as each folio should be + * at least min_nrpages anyway. + */ + if (!mapping_large_folio_support(mapping) || ra->size < min_ra_size) goto fallback; limit = min(limit, index + ra->size - 1); @@ -454,10 +477,19 @@ void page_cache_ra_order(struct readahead_control *ractl, new_order = min(mapping_max_folio_order(mapping), new_order); new_order = min_t(unsigned int, new_order, ilog2(ra->size)); + new_order = max(new_order, min_order); /* See comment in page_cache_ra_unbounded() */ nofs = memalloc_nofs_save(); filemap_invalidate_lock_shared(mapping); + /* + * If the new_order is greater than min_order and index is + * already aligned to new_order, then this will be noop as index + * aligned to new_order should also be aligned to min_order. + */ + ractl->_index = mapping_align_index(mapping, index); + index = readahead_index(ractl); + while (index <= limit) { unsigned int order = new_order; @@ -465,7 +497,7 @@ void page_cache_ra_order(struct readahead_control *ractl, if (index & ((1UL << order) - 1)) order = __ffs(index); /* Don't allocate pages past EOF */ - while (index + (1UL << order) - 1 > limit) + while (order > min_order && index + (1UL << order) - 1 > limit) order--; err = ra_alloc_folio(ractl, index, mark, order, gfp); if (err) @@ -703,8 +735,15 @@ void readahead_expand(struct readahead_control *ractl, struct file_ra_state *ra = ractl->ra; pgoff_t new_index, new_nr_pages; gfp_t gfp_mask = readahead_gfp_mask(mapping); + unsigned long min_nrpages = mapping_min_folio_nrpages(mapping); + unsigned int min_order = mapping_min_folio_order(mapping); new_index = new_start / PAGE_SIZE; + /* + * Readahead code should have aligned the ractl->_index to + * min_nrpages before calling readahead aops. + */ + VM_BUG_ON(!IS_ALIGNED(ractl->_index, min_nrpages)); /* Expand the leading edge downwards */ while (ractl->_index > new_index) { @@ -714,9 +753,11 @@ void readahead_expand(struct readahead_control *ractl, if (folio && !xa_is_value(folio)) return; /* Folio apparently present */ - folio = filemap_alloc_folio(gfp_mask, 0); + folio = filemap_alloc_folio(gfp_mask, min_order); if (!folio) return; + + index = mapping_align_index(mapping, index); if (filemap_add_folio(mapping, folio, index, gfp_mask) < 0) { folio_put(folio); return; @@ -726,7 +767,7 @@ void readahead_expand(struct readahead_control *ractl, ractl->_workingset = true; psi_memstall_enter(&ractl->_pflags); } - ractl->_nr_pages++; + ractl->_nr_pages += min_nrpages; ractl->_index = folio->index; } @@ -741,9 +782,11 @@ void readahead_expand(struct readahead_control *ractl, if (folio && !xa_is_value(folio)) return; /* Folio apparently present */ - folio = filemap_alloc_folio(gfp_mask, 0); + folio = filemap_alloc_folio(gfp_mask, min_order); if (!folio) return; + + index = mapping_align_index(mapping, index); if (filemap_add_folio(mapping, folio, index, gfp_mask) < 0) { folio_put(folio); return; @@ -753,10 +796,10 @@ void readahead_expand(struct readahead_control *ractl, ractl->_workingset = true; psi_memstall_enter(&ractl->_pflags); } - ractl->_nr_pages++; + ractl->_nr_pages += min_nrpages; if (ra) { - ra->size++; - ra->async_size++; + ra->size += min_nrpages; + ra->async_size += min_nrpages; } } }