From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: + mm-page-writebackc-write_cache_pages-deduplicate-identical-checks.patch added to -mm tree Date: Wed, 19 Feb 2020 12:18:48 -0800 Message-ID: <20200219201848.pUGx7%akpm@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:49150 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726645AbgBSUSt (ORCPT ); Wed, 19 Feb 2020 15:18:49 -0500 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: mm-commits@vger.kernel.org, jack@suse.cz, ira.weiny@intel.com, akpm@linux-foundation.org, mfo@canonical.com The patch titled Subject: mm/page-writeback.c: write_cache_pages(): deduplicate identical checks has been added to the -mm tree. Its filename is mm-page-writebackc-write_cache_pages-deduplicate-identical-checks.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-page-writebackc-write_cache_pages-deduplicate-identical-checks.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-page-writebackc-write_cache_pages-deduplicate-identical-checks.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Mauricio Faria de Oliveira Subject: mm/page-writeback.c: write_cache_pages(): deduplicate identical checks There used to be a 'retry' label in between the two (identical) checks when first introduced in commit f446daaea9d4 ("mm: implement writeback livelock avoidance using page tagging"), and later modified/updated in commit 6e6938b6d313 ("writeback: introduce .tagged_writepages for the WB_SYNC_NONE sync stage"). The label has been removed in commit 64081362e8ff ("mm/page-writeback.c: fix range_cyclic writeback vs writepages deadlock"), and the (identical) checks are now present / performed immediately one after another. So, remove/deduplicate the latter check, moving tag_pages_for_writeback() into the former check before the 'tag' variable assignment, so it's clear that it's not used in this (similarly-named) function call but only later in pagevec_lookup_range_tag(). Link: http://lkml.kernel.org/r/20200218221716.1648-1-mfo@canonical.com Signed-off-by: Mauricio Faria de Oliveira Reviewed-by: Ira Weiny Reviewed-by: Andrew Morton Cc: Jan Kara Signed-off-by: Andrew Morton --- mm/page-writeback.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/mm/page-writeback.c~mm-page-writebackc-write_cache_pages-deduplicate-identical-checks +++ a/mm/page-writeback.c @@ -2182,12 +2182,12 @@ int write_cache_pages(struct address_spa if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) range_whole = 1; } - if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) + if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) { + tag_pages_for_writeback(mapping, index, end); tag = PAGECACHE_TAG_TOWRITE; - else + } else { tag = PAGECACHE_TAG_DIRTY; - if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) - tag_pages_for_writeback(mapping, index, end); + } done_index = index; while (!done && (index <= end)) { int i; _ Patches currently in -mm which might be from mfo@canonical.com are mm-page-writebackc-write_cache_pages-deduplicate-identical-checks.patch