From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 382032F619D; Sun, 30 Aug 2026 18:43:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788115418; cv=none; b=X2stQmvGx/xpD+GINJLatTKD8LIFumQLRL0klUaQNjaa1wuHq8OjCMyYoR6Ip4R2GPZq+YpvteY/KxLE0OOPucv5I10dJ1x4VRZ37KFYj0s5o8IHWvAWkoODDuCxtijBQ3z3Ok694DcW3XP6yIo1eR+MrR2Rq02zFO1e30QDBS0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788115418; c=relaxed/simple; bh=Z4M/WPpzvepsYGJB+gWn8bv52ugodElvQ0+zzzD3630=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=iq0751hyYYwurODCfu+uYeKvZhPJdwpsKsPyYOI681HkJ4CgM1Ostg/QWmf1+TjUcsKcmc1XDFinQG3eY3CaEesDs8bfP7+pJlTSRdmlOV/ntwlHjmLygq4A74Jgb3VvC9M4z3eRHBxf47r4DP+zVEJICI2AnBgdH7t6RXJZX4k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=e0Tz3As/; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="e0Tz3As/" Received: by smtp.kernel.org (Postfix) with ESMTPS id EFA97C2BD00; Sun, 30 Aug 2026 18:43:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1788115418; bh=Z4M/WPpzvepsYGJB+gWn8bv52ugodElvQ0+zzzD3630=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=e0Tz3As/OezNV5CVe7W3YP6IKQ7VzZ2M9fPOu0zrPFlcE+DgNLYL6NGYNI1dKkD1T 4wohq+ffKmrBwCBxRVT9F3btNz3QydsSYVZFVUSR34/2v//OmjptI6UDqjWGARpYj6 auyXb10lG8TYEF/rEY93KHJu2/c0B8OFz9pnPwVF8h0IMx//qjCQZVLillJZBJOjKq VH0CCgmJDAH2UqAY0LUfoYTeS67liZY4MwK9+r3tghDOg4GHk72bwhY4HGqJ+0te5h BcAud9LbRwLzzIHWlVsv3KZJb04j0dVXaa0i2CZtN7Mt6c8WdzfbZ6F1QGgLQSIMgh F3JrGIqjcQsCA== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id D9EA2C61DE1; Sun, 30 Aug 2026 18:43:37 +0000 (UTC) From: Kairui Song via B4 Relay Date: Mon, 31 Aug 2026 02:43:34 +0800 Subject: [PATCH v4 4/6] mm/mglru: move max_seq read into walk_update_folio Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260831-mglru-flags-cleanup-v4-4-2d15dde0d7ee@tencent.com> References: <20260831-mglru-flags-cleanup-v4-0-2d15dde0d7ee@tencent.com> In-Reply-To: <20260831-mglru-flags-cleanup-v4-0-2d15dde0d7ee@tencent.com> To: linux-mm@kvack.org Cc: Andrew Morton , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Shakeel Butt , Johannes Weiner , Michal Hocko , Roman Gushchin , Muchun Song , Chris Li , Baolin Wang , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Ridong Chen , Lian Wang , Yu Zhao , Zi Yan , Qi Zheng , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Kairui Song , Kairui Song X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1788115415; l=5248; i=kasong@tencent.com; s=kasong-sign-tencent; h=from:subject:message-id; bh=MjFMt9GK+ni58sgBI6clUwzVmv/EoZkBPc5qdd6el6w=; b=OzC8dM84YUEAxm8bY4sff9mo8PnjTI/P4G95CJRxI3+jqnSHjANDU7owp297rlQqQwepJmv0q DAaRKCAcdG3DPwEwyuRHPPwcj2o59Cd6KMXlbc0n/d8j9gMyZEkn8sk X-Developer-Key: i=kasong@tencent.com; a=ed25519; pk=kCdoBuwrYph+KrkJnrr7Sm1pwwhGDdZKcKrqiK8Y1mI= X-Endpoint-Received: by B4 Relay for kasong@tencent.com/kasong-sign-tencent with auth_id=562 X-Original-From: Kairui Song Reply-To: kasong@tencent.com From: Kairui Song walk_pte_range(), walk_pmd_range_locked(), and lru_gen_look_around() each read lrugen->max_seq to compute the target generation used by walk_update_folio(), then pass it as a parameter. Move the read into walk_update_folio() itself so the callers no longer need to compute or pass the value. The max_seq read now happens once per folio update rather than once per walk range, so folios always get promoted to the current youngest generation. Reviewed-by: Baoquan He Reviewed-by: Baolin Wang Reviewed-by: Ridong Chen Reviewed-by: Lian Wang Reviewed-by: Barry Song Signed-off-by: Kairui Song --- mm/vmscan.c | 29 ++++++++++++----------------- 1 file changed, 12 insertions(+), 17 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 992d0d3e2311..88474d4af54b 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3517,13 +3517,15 @@ static bool suitable_to_scan(int total, int young) } static void walk_update_folio(struct lru_gen_mm_walk *walk, struct vm_area_struct *vma, - struct folio *folio, int new_gen, bool dirty) + struct lruvec *lruvec, struct folio *folio, bool dirty) { - int old_gen; + int new_gen, old_gen; if (!folio) return; + new_gen = lru_gen_from_seq(READ_ONCE(lruvec->lrugen.max_seq)); + if (dirty && !folio_test_dirty(folio) && !(folio_test_anon(folio) && folio_test_swapbacked(folio) && !folio_test_swapcache(folio))) @@ -3554,8 +3556,6 @@ static bool walk_pte_range(pmd_t *pmd, unsigned long start, unsigned long end, struct lru_gen_mm_walk *walk = args->private; struct mem_cgroup *memcg = lruvec_memcg(walk->lruvec); struct pglist_data *pgdat = lruvec_pgdat(walk->lruvec); - DEFINE_MAX_SEQ(walk->lruvec); - int gen = lru_gen_from_seq(max_seq); unsigned int nr; pmd_t pmdval; @@ -3606,7 +3606,7 @@ static bool walk_pte_range(pmd_t *pmd, unsigned long start, unsigned long end, continue; if (last != folio) { - walk_update_folio(walk, args->vma, last, gen, dirty); + walk_update_folio(walk, args->vma, walk->lruvec, last, dirty); last = folio; dirty = false; @@ -3619,7 +3619,7 @@ static bool walk_pte_range(pmd_t *pmd, unsigned long start, unsigned long end, walk->mm_stats[MM_LEAF_YOUNG] += nr; } - walk_update_folio(walk, args->vma, last, gen, dirty); + walk_update_folio(walk, args->vma, walk->lruvec, last, dirty); last = NULL; if (i < PTRS_PER_PTE && get_next_vma(PMD_MASK, PAGE_SIZE, args, &start, &end)) @@ -3642,8 +3642,6 @@ static void walk_pmd_range_locked(pud_t *pud, unsigned long addr, struct vm_area struct lru_gen_mm_walk *walk = args->private; struct mem_cgroup *memcg = lruvec_memcg(walk->lruvec); struct pglist_data *pgdat = lruvec_pgdat(walk->lruvec); - DEFINE_MAX_SEQ(walk->lruvec); - int gen = lru_gen_from_seq(max_seq); VM_WARN_ON_ONCE(pud_leaf(*pud)); @@ -3697,7 +3695,7 @@ static void walk_pmd_range_locked(pud_t *pud, unsigned long addr, struct vm_area goto next; if (last != folio) { - walk_update_folio(walk, vma, last, gen, dirty); + walk_update_folio(walk, vma, walk->lruvec, last, dirty); last = folio; dirty = false; @@ -3711,7 +3709,7 @@ static void walk_pmd_range_locked(pud_t *pud, unsigned long addr, struct vm_area i = i > MIN_LRU_BATCH ? 0 : find_next_bit(bitmap, MIN_LRU_BATCH, i) + 1; } while (i <= MIN_LRU_BATCH); - walk_update_folio(walk, vma, last, gen, dirty); + walk_update_folio(walk, vma, walk->lruvec, last, dirty); lazy_mmu_mode_disable(); spin_unlock(ptl); @@ -4275,8 +4273,6 @@ bool lru_gen_look_around(struct page_vma_mapped_walk *pvmw, unsigned int nr) struct pglist_data *pgdat = folio_pgdat(folio); struct lruvec *lruvec; struct lru_gen_mm_state *mm_state; - unsigned long max_seq; - int gen; lockdep_assert_held(pvmw->ptl); VM_WARN_ON_ONCE_FOLIO(folio_test_lru(folio), folio); @@ -4313,8 +4309,6 @@ bool lru_gen_look_around(struct page_vma_mapped_walk *pvmw, unsigned int nr) memcg = get_mem_cgroup_from_folio(folio); lruvec = mem_cgroup_lruvec(memcg, pgdat); - max_seq = READ_ONCE((lruvec)->lrugen.max_seq); - gen = lru_gen_from_seq(max_seq); mm_state = get_mm_state(lruvec); lazy_mmu_mode_enable(); @@ -4346,7 +4340,7 @@ bool lru_gen_look_around(struct page_vma_mapped_walk *pvmw, unsigned int nr) continue; if (last != folio) { - walk_update_folio(walk, vma, last, gen, dirty); + walk_update_folio(walk, vma, lruvec, last, dirty); last = folio; dirty = false; @@ -4358,13 +4352,14 @@ bool lru_gen_look_around(struct page_vma_mapped_walk *pvmw, unsigned int nr) young += nr; } - walk_update_folio(walk, vma, last, gen, dirty); + walk_update_folio(walk, vma, lruvec, last, dirty); lazy_mmu_mode_disable(); /* feedback from rmap walkers to page table walkers */ if (mm_state && suitable_to_scan(i, young)) - update_bloom_filter(mm_state, max_seq, pvmw->pmd); + update_bloom_filter(mm_state, READ_ONCE(lruvec->lrugen.max_seq), + pvmw->pmd); mem_cgroup_put(memcg); -- 2.55.0