From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794600348; b=DHQOFfN890ge56yp5Z+f1JIrB27n84WTWB5/hjmZmgWXxD8r3MkM3HqJLXtLi1wKe1Q7 hM/R+t5Xl61YvQN2RcDnTcyiA22h2cN4CoYX7u/D4M0cFV6MprUerv1NiT/EpGchPgOAx a5HkDymDq1nSUl74e+VYsN0gBQH/wBcsytcAUepWqrE/FPRPv0sYhiHcEZ47FB+hgVyGE FrnGrn0gOhBzr3vocn8BxkrRXq+DxBgXhQtLolJC2irKTnEErEetAUrVPI74y/kL0/uQJ kcwFQQqqzwvSAoRJOHlU2jecIvQV+BmXfe80ZSv7s0D5DRSKKKilj9zO9OPjeqwhsAQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794600348; h=Received:DKIM-Signature:Date:To:From:Subject:Message-Id; bh=Fcj/Rz5XIswLoKDAFhjuGNYLz9xhX1wisfJh4U98R/o=; b=oU4YJept5rcX/ykUfmErt6EnNpn6Mu5btGwCzc/0FtYIlWWiv24QRMm9S5GWCHhQbSAY SIA2XcvKEUEVNo7rFqtMXyHr836JlyHfL7seIGFmlpPJWf7QVKghOZWfEBrtT+45e0YBc xp/VC990TE/EptnexPr3TWs2IrasYqPwlEmjTCnvHEL68nq1R5gyEAh9/QcKf/DeuCEzP 1FJ30XHFEl2yHKWdhIb7/ng3AV/WdnvoB3zsqAZ/hmw2hs2BKnu4YE554BBiBjeKkvla+ rpY6YZ3/i9vEq6zKv/FsJtC+D8Oy4Z8dwzL3XrDjqlHVuJ0O+Kfi3WP8YoJj0lHIoAw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b=P6IMPtAQ; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6C6D7606A337 for ; Fri, 13 Nov 2026 20:05:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b=P6IMPtAQ Received: by smtp.kernel.org (Postfix) with ESMTPSA id 067F61F000C5; Fri, 13 Nov 2026 20:05:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1794600348; bh=Fcj/Rz5XIswLoKDAFhjuGNYLz9xhX1wisfJh4U98R/o=; h=Date:To:From:Subject; b=P6IMPtAQF3/iPCJagZkAZkvLUEQT7puWzRTmkIL3Ue3GsdVpFIRseQMfP6tyIeMAD LMTzBGAZld+FTprlJU2HQasQ1Z2HNXWsSUWVPt8SqWY6+ImRWOB/Rp+mpQMeBK4TCT 4zdUzvdTI9jzyt6wpD80jpf30MY6VkbnQy+wcdX0= Date: Fri, 13 Nov 2026 12:05:47 -0800 To: mm-commits@vger.kernel.org,baohua@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-mglru-run-aging-when-one-type-has-no-populatable-folios.patch added to mm-new branch Message-Id: <20261113200548.067F61F000C5@smtp.kernel.org> X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list The patch titled Subject: mm/mglru: run aging when one type has no populatable folios has been added to the -mm mm-new branch. Its filename is mm-mglru-run-aging-when-one-type-has-no-populatable-folios.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mglru-run-aging-when-one-type-has-no-populatable-folios.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. The mm-new branch of mm.git is not included in linux-next If a few days of testing in mm-new is successful, the patch will me moved into mm.git's mm-unstable branch, which is included in linux-next 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 via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: "Barry Song (Xiaomi)" Subject: mm/mglru: run aging when one type has no populatable folios Date: Sat, 14 Nov 2026 02:55:36 +0800 We may have scan budget remaining for anon or file but no folios in populatable generations to scan. In this case, `scan_folios()` may waste time scanning that type while the other type still has populatable folios. Run aging in this case to make more folios populatable. This also helps respect the scan budget distribution determined by swappiness. To avoid excessive aging, allow no-populatable aging only once per `try_to_shrink_lruvec()` invocation. With extreme swappiness values such as 1 and 200, reclaim initially focuses exclusively on the preferred type. In this case, defer aging the lagging type until `sc->priority` reaches `DEF_PRIORITY / 2`. This avoids unnecessary aging and has shown better performance in testing. Link: https://lore.kernel.org/20261113185541.70203-12-baohua@kernel.org Signed-off-by: Barry Song (Xiaomi) Signed-off-by: Andrew Morton Cc: Axel Rasmussen Cc: Baolin Wang Cc: Baoquan He Cc: Johannes Weiner Cc: Cc: Kairui Song Cc: Kunwu Chan Cc: Liam R. Howlett Cc: wang lian Cc: Cc: Cc: Michal Hocko Cc: Qi Zheng Cc: Ridong Chen Cc: Mike Rapoport Cc: Shakeel Butt Cc: Suren Baghdasaryan Cc: wangzicheng Cc: Wei Xu Cc: Yuanchu Xie Cc: Bo Zhang Cc: Hui Zhu Cc: Siddharth Chintamaneni Cc: Bo Zhang --- mm/vmscan.c | 49 ++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 38 insertions(+), 11 deletions(-) --- a/mm/vmscan.c~mm-mglru-run-aging-when-one-type-has-no-populatable-folios +++ a/mm/vmscan.c @@ -5109,7 +5109,8 @@ static bool lru_gen_imbalanced(struct lr } static bool should_run_aging(struct lruvec *lruvec, unsigned long max_seq, - struct scan_control *sc, int swappiness) + struct scan_control *sc, int swappiness, + bool no_populatable) { DEFINE_MIN_SEQ(lruvec); @@ -5121,6 +5122,13 @@ static bool should_run_aging(struct lruv if (sc->priority == DEF_PRIORITY) return false; + /* + * Run aging if scan budget remains but no folios + * in populatable generations are available to scan. + */ + if (no_populatable) + return true; + /* better to run aging even though eviction is still possible */ if (evictable_min_seq(min_seq, swappiness) + MIN_NR_GENS == max_seq) return true; @@ -5208,6 +5216,13 @@ static bool try_to_shrink_lruvec(struct bool need_rotate = false, should_age = false; int swappiness = get_swappiness(lruvec, sc); struct mem_cgroup *memcg = lruvec_memcg(lruvec); + /* + * Avoid aging the lagging type under extreme swappiness, + * as reclaim of the unpreferred type is disabled until + * DEF_PRIORITY / 2. + */ + bool allow_no_populatable_age = (sc->priority <= DEF_PRIORITY / 2) || + (swappiness > MIN_SWAPPINESS + 1 && swappiness < MAX_SWAPPINESS); /* * Proactive reclaim initiated by userspace for anonymous memory only. @@ -5225,22 +5240,19 @@ static bool try_to_shrink_lruvec(struct lru_gen_prepare_scan(lruvec, sc, memcg, swappiness, nr); while (nr[LRU_GEN_ANON] > 0 || nr[LRU_GEN_FILE] > 0) { - DEFINE_MAX_SEQ(lruvec); + unsigned long orig_file, orig_anon; + unsigned long max_seq; + bool no_populatable; + long scanned; if (mem_cgroup_below_min(sc->target_mem_cgroup, memcg)) { need_rotate = true; break; } - if (should_run_aging(lruvec, max_seq, sc, swappiness)) { - trace_mm_mglru_aging(lruvec, sc, swappiness); - if (try_to_inc_max_seq(lruvec, max_seq, swappiness, false)) - need_rotate = true; - should_age = true; - } - - if (!evict_folio_lists(nr, lruvec, sc, swappiness, MIN_LRU_BATCH)) - break; + orig_anon = nr[LRU_GEN_ANON]; + orig_file = nr[LRU_GEN_FILE]; + scanned = evict_folio_lists(nr, lruvec, sc, swappiness, MIN_LRU_BATCH); if (should_abort_scan(lruvec, sc)) break; @@ -5252,6 +5264,21 @@ static bool try_to_shrink_lruvec(struct if (root_reclaim(sc) && should_age) break; + /* Limit no_populatable aging to once per try_to_shrink_lruvec() */ + no_populatable = allow_no_populatable_age && + ((nr[LRU_GEN_ANON] && nr[LRU_GEN_ANON] == orig_anon) || + (nr[LRU_GEN_FILE] && nr[LRU_GEN_FILE] == orig_file)); + allow_no_populatable_age &= !no_populatable; + max_seq = READ_ONCE((lruvec)->lrugen.max_seq); + if (should_run_aging(lruvec, max_seq, sc, swappiness, no_populatable)) { + trace_mm_mglru_aging(lruvec, sc, swappiness); + if (try_to_inc_max_seq(lruvec, max_seq, swappiness, false)) + need_rotate = true; + should_age = true; + } + if (!scanned) + break; + cond_resched(); } _ Patches currently in -mm which might be from baohua@kernel.org are arm64-vmalloc-allow-arch_vmap_pte_range_map_size-to-batch-multiple-cont_pte.patch mm-vmalloc-extend-page-table-walk-to-support-larger-page_shift-sizes-and-eliminate-page-table-rewalk.patch mm-vmalloc-map-contiguous-pages-in-batches-for-vmap-if-possible.patch mm-vmalloc-align-vm_area-so-vmap-can-batch-mappings.patch mm-mglru-avoid-placing-rejected-folios-below-populated-gen.patch mm-mglru-run-aging-when-one-type-has-no-populatable-folios.patch mm-mglru-restrict-eviction-accounting-to-eligible-zones.patch mm-mglru-reduce-lru-lock-contention-by-shrinking-folio-batches-in-inc_min_seq.patch mm-mglru-make-swappiness=1-file-reclaim-more-aggressive.patch