From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DF1EB4A5C3F for ; Wed, 16 Sep 2026 22:29:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789597759; cv=none; b=R4eLIBQih8+LizC+IRbdPBaZ04w1gIGoSGRRdOqvuHUDF/ZkI8LZ/LMxjfQpYC4j2wBA/9gDWrbTko1fYcPf1PBlQNdeU9V2bseFzK9hUx3nS81+7zx1rJCgTsllY5fJcZ4G2bYtznZ961iW/HUJ9vJGcCN34RCRIlYK5A67TOg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789597759; c=relaxed/simple; bh=D2s9WVviLlP4wVGRKezV1g65qtkNIbOaf+Um0uKXYW0=; h=Date:To:From:Subject:Message-Id; b=ezoWTjPcPjb0iRGjkYeKkSZJw1ZJrULWDGz3Tr13BeDhqaNBzwVCfFTPmvP6IFfR7eIm4dbajm1U06bTIQZ3JyipqAUz6sM/y1qDzLjOf4pLvY+Z1668Vs+0tsFSxxoWQgu9cOOg8pJdLQrLSA6LhoBRc/GVzrMpd39U7/8Y3rE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=ANbYaJl5; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="ANbYaJl5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3E2411F000FF; Wed, 16 Sep 2026 22:29:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1789597752; bh=Ut3TcV5Ek3zRBBtrnBHrGMIRXPEzFCY4+/TZRpHtIII=; h=Date:To:From:Subject; b=ANbYaJl5bSJdQ5//HmmUmsWpN+3bTNeWYq8TJhiErHM1bEuYZ8WS45vOuQWolROLg 3awcneGeCZM8WID8rQKkfUsl1O9/8sSRfsuJBsjzuiKqmp6efrCgtv/wV9FYXQx//H H+tc48CnaWgPPKdOsoykMvG27UlSsxLBjR2olJrs= Date: Wed, 16 Sep 2026 15:29:11 -0700 To: mm-commits@vger.kernel.org,willy@infradead.org,shakeel.butt@linux.dev,roman.gushchin@linux.dev,riel@surriel.com,muchun.song@linux.dev,mhocko@kernel.org,jack@suse.cz,hannes@cmpxchg.org,david@kernel.org,usama.arif@linux.dev,akpm@linux-foundation.org From: Andrew Morton Subject: [alternative-merged] mm-filemap-move-lruvec-accounting-outside-the-xarray-lock-v5.patch removed from -mm tree Message-Id: <20260916222912.3E2411F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm: filemap: move lruvec accounting outside the xarray lock has been removed from the -mm tree. Its filename was mm-filemap-move-lruvec-accounting-outside-the-xarray-lock-v5.patch This patch was dropped because an alternative patch was or shall be merged ------------------------------------------------------ From: Usama Arif Subject: mm: filemap: move lruvec accounting outside the xarray lock Date: Wed, 16 Sep 2026 05:51:22 -0700 __filemap_add_folio() inserts a folio and updates mapping->nrpages while holding mapping->i_pages.xa_lock with interrupts disabled. The XArray insertion and nrpages update require the lock, but the lruvec statistic updates do not. With CONFIG_MEMCG, those calls also update per-CPU memcg and lruvec counters and notify cgroup rstat, extending the critical section. Move the lruvec accounting after a successful XArray insertion and after xas_unlock_irq(). The page-cache references pin the folio, while the folio lock keeps folio->mapping stable and prevents removal until accounting is complete. This moves one lruvec update for ordinary folios and a second for PMD-mappable folios out of the serialized section. In a 30-second system-wide perf lock contention -ab capture on a production host, the hottest caller-stack record attributed to __filemap_add_folio() had 20,867 contentions and 557.930 ms total wait. That was 14% of the 3.998 seconds of aggregate lock wait in the capture. Moving lruvec accuting outside of critical section should help optimize it. Link: https://lore.kernel.org/20260916125122.2696271-1-usama.arif@linux.dev Signed-off-by: Usama Arif Signed-off-by: Andrew Morton Cc: David Hildenbrand Cc: Jan Kara Cc: Johannes Weiner Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Muchun Song Cc: Rik van Riel Cc: Roman Gushchin Cc: Shakeel Butt --- mm/filemap.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) --- a/mm/filemap.c~mm-filemap-move-lruvec-accounting-outside-the-xarray-lock-v5 +++ a/mm/filemap.c @@ -918,14 +918,6 @@ noinline int __filemap_add_folio(struct mapping->nrpages += nr; - /* hugetlb pages do not participate in page cache accounting */ - if (!huge) { - lruvec_stat_mod_folio(folio, NR_FILE_PAGES, nr); - if (folio_test_pmd_mappable(folio)) - lruvec_stat_mod_folio(folio, - NR_FILE_THPS, nr); - } - unlock: xas_unlock_irq(&xas); @@ -942,6 +934,13 @@ unlock: if (xas_error(&xas)) goto error; + /* hugetlb pages do not participate in page cache accounting */ + if (!huge) { + lruvec_stat_mod_folio(folio, NR_FILE_PAGES, nr); + if (folio_test_pmd_mappable(folio)) + lruvec_stat_mod_folio(folio, NR_FILE_THPS, nr); + } + trace_mm_filemap_add_to_page_cache(folio); return 0; error: _ Patches currently in -mm which might be from usama.arif@linux.dev are mm-zswap-dont-fail-a-large-folio-swapin-whose-range-is-not-in-zswap.patch