From nobody Fri Dec 19 19:13:55 2025 Received: from out-171.mta0.migadu.com (out-171.mta0.migadu.com [91.218.175.171]) (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 0051121772A for ; Wed, 17 Dec 2025 07:29:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.171 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765956586; cv=none; b=Ucni1dDsPTY0tGlv9eAXa4k6o+M9j+ANL/T59fygpvjP89s2ZCwOYFg0cLiYP0KF939DX3BJXgqoZh9oqc8xS4t2UF+UmTfKG2lq3lB17h4qNjOpnPFWVghOtthteK9kudDRsf+mVYBTo+RlYRF0aiIA2Sy9Ld7QFFC0C7eSbVg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765956586; c=relaxed/simple; bh=8vgx2ykexnnO8DAvB1JfddChw0WTru0tk8binaaVqjU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mrp1RaUDY70fhpOXo/YR79HXKDbiz2G9HcqAmbh+CROaQH+V2VB4QA28ZtmmsEKS7qZ/5vo1IYp1wSAvFwfK81s2H1dml2L7Ft9j8m84sRreseIkStaxmQEfD0j3rI4Nwh419RhHwwlb3saLE/p7gsbXON++nOtBJSvZAQnSmjE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=G49xQSCD; arc=none smtp.client-ip=91.218.175.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="G49xQSCD" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1765956577; 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=Q0OheEBAXk7XPYwqSkJ0Le26eixYKExsbR31tbstIws=; b=G49xQSCDDpZAppo/wZsDsqQWibcEkNZSb7m2ERxT7qti7MrBuU10SmnxCYBc+WUIHf4TCS iMR8QuBNfphzQC4ptasTWFpd/SM2MIr5k84EuasV7jJsBHSTrlV0TZPz/uS0quxKVuaEio Rs436+PJI9YW/vq4R6xRXGnOPF2R2A4= From: Qi Zheng To: hannes@cmpxchg.org, hughd@google.com, mhocko@suse.com, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev, david@kernel.org, lorenzo.stoakes@oracle.com, ziy@nvidia.com, harry.yoo@oracle.com, imran.f.khan@oracle.com, kamalesh.babulal@oracle.com, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, chenridong@huaweicloud.com, mkoutny@suse.com, akpm@linux-foundation.org, hamzamahfooz@linux.microsoft.com, apais@linux.microsoft.com, lance.yang@linux.dev Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Muchun Song , Qi Zheng Subject: [PATCH v2 05/28] mm: vmscan: refactor move_folios_to_lru() Date: Wed, 17 Dec 2025 15:27:29 +0800 Message-ID: <0140f3b290fd259d58e11f86f1f04f732e8096f1.1765956025.git.zhengqi.arch@bytedance.com> In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" From: Muchun Song In a subsequent patch, we'll reparent the LRU folios. The folios that are moved to the appropriate LRU list can undergo reparenting during the move_folios_to_lru() process. Hence, it's incorrect for the caller to hold a lruvec lock. Instead, we should utilize the more general interface of folio_lruvec_relock_irq() to obtain the correct lruvec lock. This patch involves only code refactoring and doesn't introduce any functional changes. Signed-off-by: Muchun Song Acked-by: Johannes Weiner Signed-off-by: Qi Zheng Acked-by: Shakeel Butt --- mm/vmscan.c | 46 +++++++++++++++++++++------------------------- 1 file changed, 21 insertions(+), 25 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 49e5661746213..354b19f7365d4 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1883,24 +1883,27 @@ static bool too_many_isolated(struct pglist_data *p= gdat, int file, /* * move_folios_to_lru() moves folios from private @list to appropriate LRU= list. * - * Returns the number of pages moved to the given lruvec. + * Returns the number of pages moved to the appropriate lruvec. + * + * Note: The caller must not hold any lruvec lock. */ -static unsigned int move_folios_to_lru(struct lruvec *lruvec, - struct list_head *list) +static unsigned int move_folios_to_lru(struct list_head *list) { int nr_pages, nr_moved =3D 0; + struct lruvec *lruvec =3D NULL; struct folio_batch free_folios; =20 folio_batch_init(&free_folios); while (!list_empty(list)) { struct folio *folio =3D lru_to_folio(list); =20 + lruvec =3D folio_lruvec_relock_irq(folio, lruvec); VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); list_del(&folio->lru); if (unlikely(!folio_evictable(folio))) { - spin_unlock_irq(&lruvec->lru_lock); + lruvec_unlock_irq(lruvec); folio_putback_lru(folio); - spin_lock_irq(&lruvec->lru_lock); + lruvec =3D NULL; continue; } =20 @@ -1922,19 +1925,15 @@ static unsigned int move_folios_to_lru(struct lruve= c *lruvec, =20 folio_unqueue_deferred_split(folio); if (folio_batch_add(&free_folios, folio) =3D=3D 0) { - spin_unlock_irq(&lruvec->lru_lock); + lruvec_unlock_irq(lruvec); mem_cgroup_uncharge_folios(&free_folios); free_unref_folios(&free_folios); - spin_lock_irq(&lruvec->lru_lock); + lruvec =3D NULL; } =20 continue; } =20 - /* - * All pages were isolated from the same lruvec (and isolation - * inhibits memcg migration). - */ VM_BUG_ON_FOLIO(!folio_matches_lruvec(folio, lruvec), folio); lruvec_add_folio(lruvec, folio); nr_pages =3D folio_nr_pages(folio); @@ -1943,11 +1942,12 @@ static unsigned int move_folios_to_lru(struct lruve= c *lruvec, workingset_age_nonresident(lruvec, nr_pages); } =20 + if (lruvec) + lruvec_unlock_irq(lruvec); + if (free_folios.nr) { - spin_unlock_irq(&lruvec->lru_lock); mem_cgroup_uncharge_folios(&free_folios); free_unref_folios(&free_folios); - spin_lock_irq(&lruvec->lru_lock); } =20 return nr_moved; @@ -2016,8 +2016,7 @@ static unsigned long shrink_inactive_list(unsigned lo= ng nr_to_scan, nr_reclaimed =3D shrink_folio_list(&folio_list, pgdat, sc, &stat, false, lruvec_memcg(lruvec)); =20 - spin_lock_irq(&lruvec->lru_lock); - move_folios_to_lru(lruvec, &folio_list); + move_folios_to_lru(&folio_list); =20 mod_lruvec_state(lruvec, PGDEMOTE_KSWAPD + reclaimer_offset(sc), stat.nr_demoted); @@ -2028,6 +2027,7 @@ static unsigned long shrink_inactive_list(unsigned lo= ng nr_to_scan, count_memcg_events(lruvec_memcg(lruvec), item, nr_reclaimed); count_vm_events(PGSTEAL_ANON + file, nr_reclaimed); =20 + spin_lock_irq(&lruvec->lru_lock); lru_note_cost_unlock_irq(lruvec, file, stat.nr_pageout, nr_scanned - nr_reclaimed); =20 @@ -2166,16 +2166,14 @@ static void shrink_active_list(unsigned long nr_to_= scan, /* * Move folios back to the lru list. */ - spin_lock_irq(&lruvec->lru_lock); - - nr_activate =3D move_folios_to_lru(lruvec, &l_active); - nr_deactivate =3D move_folios_to_lru(lruvec, &l_inactive); + nr_activate =3D move_folios_to_lru(&l_active); + nr_deactivate =3D move_folios_to_lru(&l_inactive); =20 count_vm_events(PGDEACTIVATE, nr_deactivate); count_memcg_events(lruvec_memcg(lruvec), PGDEACTIVATE, nr_deactivate); - mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, -nr_taken); =20 + spin_lock_irq(&lruvec->lru_lock); lru_note_cost_unlock_irq(lruvec, file, 0, nr_rotated); trace_mm_vmscan_lru_shrink_active(pgdat->node_id, nr_taken, nr_activate, nr_deactivate, nr_rotated, sc->priority, file); @@ -4736,14 +4734,14 @@ static int evict_folios(unsigned long nr_to_scan, s= truct lruvec *lruvec, set_mask_bits(&folio->flags.f, LRU_REFS_FLAGS, BIT(PG_active)); } =20 - spin_lock_irq(&lruvec->lru_lock); - - move_folios_to_lru(lruvec, &list); + move_folios_to_lru(&list); =20 walk =3D current->reclaim_state->mm_walk; if (walk && walk->batched) { walk->lruvec =3D lruvec; + spin_lock(&lruvec->lru_lock); reset_batch_size(walk); + spin_unlock(&lruvec->lru_lock); } =20 mod_lruvec_state(lruvec, PGDEMOTE_KSWAPD + reclaimer_offset(sc), @@ -4755,8 +4753,6 @@ static int evict_folios(unsigned long nr_to_scan, str= uct lruvec *lruvec, count_memcg_events(memcg, item, reclaimed); count_vm_events(PGSTEAL_ANON + type, reclaimed); =20 - spin_unlock_irq(&lruvec->lru_lock); - list_splice_init(&clean, &list); =20 if (!list_empty(&list)) { --=20 2.20.1