From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk2-f13.google.com (mail-qk2-f13.google.com [74.125.230.205]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8FC42530DEA for ; Tue, 22 Sep 2026 23:58:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.230.205 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790121525; cv=none; b=nrcABKULKJtJsMKOQZ2BctO6IfBL/1KLvvC5vov0EHsJInEVmWGG+jxOx7qJfzXSpIBU7p+uvBAhm9nOXrP/CDjorbnamYBP2JtulOe/aQnXPeuk3WnMMNudyEwCuzy8WHqUApKyA6qR7Gu3VsWv6W8VgPiNVWUlLDegq/xL4TI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790121525; c=relaxed/simple; bh=Z+b3w7hN29ny0n+lgoibjklp6h6u1gN7hC/nkJ+vNU8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=is12o8ZmmqU1MLjbO5de5SQ9Xsimy+KFy2OCOhh3QC33VErx+fk14HM8vLYioKg32HTHGxFRfTIoHdKkHZW9NiSBJNF56Cn63+2H4p7sfNPtblPAReBS86s1sRwTfT3ktIzwYqBTIuTFQw+j+DKCK4yxehYg0zo3Lv/v+QCOdak= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gourry.net; spf=pass smtp.mailfrom=gourry.net; dkim=pass (2048-bit key) header.d=gourry.net header.i=@gourry.net header.b=h4a7kRms; arc=none smtp.client-ip=74.125.230.205 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gourry.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gourry.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gourry.net header.i=@gourry.net header.b="h4a7kRms" Received: by mail-qk2-f13.google.com with SMTP id d75a77b69052e-530e2f50d01so4353641cf.0 for ; Tue, 22 Sep 2026 16:58:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gourry.net; s=google; t=1790121519; x=1790726319; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=/oNw9RPMr3V+/qUjJEYCXBc3lvf+tyCPjegYTQeEM3I=; b=h4a7kRms1pVwjzo/b9JB0U2KBFZevFmriKnNg9xWLUdLS4HzGrr7Hgq5DEYfM0CBtt ja1SI+7RiMU4DIxB9uFwo/rMyh78MRAwQlyFo2daQwwO+qsGgvYTrmplIRg2ogP6/oWh haOg5p534kDxTnhIiO0k+u37KE6dRuj31PJ5zwsEnsfz1+QTqX7S1H6pL+eDqKE8fqms eQHjfkpN2/C9RPQKwPAzzyKlEQ5F/Azhn9PgtX6UBmlaU0NJXQCqjLuzPcgJZtLbOebY SyDZdD6mfvMjznc5VvZxNrYF3adzn56iSpuTK6+dijswNE5ggT5Zv3lbONkUntKrvaI3 yVAg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790121519; x=1790726319; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=/oNw9RPMr3V+/qUjJEYCXBc3lvf+tyCPjegYTQeEM3I=; b=PrjmpupJKxoFyG0p7JdftTWIftgxQTZ3YTMgTixvNiufPriDBGmL6tlYjZ+0T8BSZO UJBG5pIWeO3GB3KjoDP+2uuqgaqJw4X9cwvfdSSqQF+sM/sUPn7A/OvihlcXv3KRbubY zRbgMbdQq+fyviaFL6yxRkAZMF8MgUTdpJQWy30m/FlghSKSiWYZHGgVuyzW/0Ef1aoS KejBGVY5WJzSATqsD2euqeQ1IcDPunIiDuTazTTX2H14m5E9bdWQJOgq3D1Wp5IJjuur D28+acE3uBhyMUQTIwXorLQzYpJ8cicxeZfdeqFAFAYpFHyQHTZb++hd3GwG2hPbyi8+ NElg== X-Gm-Message-State: AFuF++mim/fRaQsdnq2IwVMjdAy2/xgwPGdPTKXDPpLkK2sReKiCgzER VGYXzh2vfXqVyIqJbsCioFb6/nd3Jb3lOE2dDpL+GkeR2eb6RixfHLYV/ql6Gn0naeA= X-Gm-Gg: AYBFou0bC8kP9HIXlBdjjb+9yE+NZp+XGl6RXwirEuwU6085UUycIedGGK67jPmV2ly t8W6vL5JsOBsa1kL7fFY2KO98UlEhFQv1KU7iACy+4HmgI297uf9qQD3YhKZRo/ULdW92DHdqtz 3HSanN3Vhj3+qI/OAU+tD4t074i8yk2pUO8wS9BJ+qeaL/iDk0/iRjbPxkYW90je/NzcmC0dNRO UtwPPh6iGVnMk25G4YvRhY5HBCLQ9tN9eVYzYxUbOq0CcGwGsuE4QTpqWSL1bGpykvXWeCgNNeb /2Tzde66fxZ9ugJY484pXZFaIZZUQTh/BonhozK7wDEUYoxoYZgNyH1oimvkar+mgfdwqS4mUnX IexGPMXosvXknnPBzfF7roB0tUXVD8OtDefILocFN6WHOjdSrsEa8DBJr9fQb3Lfr174WsiG8Ra uojyHFeL5u9Dg2LdEsYPeuesF0XimfX5WAFWKNOa70aKz1LfLGroNO2YyjBRzjaztNYgLkatxxN Q/kZF5soAgWnufJCyjDIOfHtha2454cl7vGsWRP9AY9iPcxoWpqEwjet+u80Dz355Im7+0= X-Received: by 2002:a05:622a:305:b0:530:f77a:89aa with SMTP id d75a77b69052e-532eacb0064mr19428811cf.30.1790121519361; Tue, 22 Sep 2026 16:58:39 -0700 (PDT) Received: from gourry-fedora-PF4VCD3F.lan (pool-173-79-60-52.washdc.fios.verizon.net. [173.79.60.52]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-532eb3c6715sm8323261cf.30.2026.09.22.16.58.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 22 Sep 2026 16:58:39 -0700 (PDT) From: Gregory Price To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, kernel-team@meta.com, akpm@linux-foundation.org, liam@infradead.org, ljs@kernel.org, david@kernel.org, vbabka@kernel.org, jannh@google.com, rppt@kernel.org, surenb@google.com, mhocko@suse.com, shuah@kernel.org, "Gregory Price (Meta)" Subject: [PATCH 03/10] mm/madvise: factor shared LRU folio handling Date: Tue, 22 Sep 2026 19:58:23 -0400 Message-ID: <20260922235830.2350770-4-gourry@gourry.net> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260922235830.2350770-1-gourry@gourry.net> References: <20260922235830.2350770-1-gourry@gourry.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The huge-PMD and PTE paths duplicate folio filtering, reference clearing, deactivation and pageout isolation. Keeping both copies synchronized obscures the page-table-specific control flow. Factor the common filtering and LRU operation into helpers. Keep the lock-before-reference sequence visible at each split site because an early reference can prevent split_folio() from succeeding. No functional change intended. Assisted-by: LLM Signed-off-by: Gregory Price (Meta) --- mm/madvise.c | 90 +++++++++++++++++++++++++--------------------------- 1 file changed, 43 insertions(+), 47 deletions(-) diff --git a/mm/madvise.c b/mm/madvise.c index 83d54ab385da8..c345fef23f15d 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -361,6 +361,39 @@ static inline int madvise_folio_pte_batch(unsigned long addr, unsigned long end, FPB_MERGE_YOUNG_DIRTY); } +static inline void +madvise_lru_folio(struct folio *folio, bool pageout, + struct list_head *folio_list) +{ + /* + * Clear references before deactivating or reclaiming the folio. This can + * make idle-page tracking miss recent accesses. + */ + folio_clear_referenced(folio); + folio_test_clear_young(folio); + if (folio_test_active(folio)) + folio_set_workingset(folio); + + if (!pageout) { + folio_deactivate(folio); + return; + } + + if (!folio_isolate_lru(folio)) + return; + if (folio_test_unevictable(folio)) + folio_putback_lru(folio); + else + list_add(&folio->lru, folio_list); +} + +static bool madvise_lru_folio_is_filtered(struct folio *folio, + bool pageout_anon_only) +{ + return folio_maybe_mapped_shared(folio) || + (pageout_anon_only && !folio_test_anon(folio)); +} + static int madvise_lru_pmd_entry(pmd_t *pmd, unsigned long addr, unsigned long end, struct mm_walk *walk) { @@ -373,15 +406,14 @@ static int madvise_lru_pmd_entry(pmd_t *pmd, unsigned long addr, spinlock_t *ptl; struct folio *folio = NULL; LIST_HEAD(folio_list); - bool pageout_anon_only_filter; unsigned int batch_count = 0; + bool pageout_anon_only; int nr; if (fatal_signal_pending(current)) return -EINTR; - - pageout_anon_only_filter = pageout && !vma_is_anonymous(vma) && - !can_do_file_pageout(vma); + pageout_anon_only = pageout && !vma_is_anonymous(vma) && + !can_do_file_pageout(vma); #ifdef CONFIG_TRANSPARENT_HUGEPAGE if (pmd_trans_huge(*pmd)) { @@ -407,11 +439,7 @@ static int madvise_lru_pmd_entry(pmd_t *pmd, unsigned long addr, if (folio_is_zone_device(folio)) goto huge_unlock; - /* Do not interfere with other mappings of this folio */ - if (folio_maybe_mapped_shared(folio)) - goto huge_unlock; - - if (pageout_anon_only_filter && !folio_test_anon(folio)) + if (madvise_lru_folio_is_filtered(folio, pageout_anon_only)) goto huge_unlock; if (next - addr != HPAGE_PMD_SIZE) { @@ -437,19 +465,7 @@ static int madvise_lru_pmd_entry(pmd_t *pmd, unsigned long addr, tlb_remove_pmd_tlb_entry(tlb, pmd, addr); } - folio_clear_referenced(folio); - folio_test_clear_young(folio); - if (folio_test_active(folio)) - folio_set_workingset(folio); - if (pageout) { - if (folio_isolate_lru(folio)) { - if (folio_test_unevictable(folio)) - folio_putback_lru(folio); - else - list_add(&folio->lru, &folio_list); - } - } else - folio_deactivate(folio); + madvise_lru_folio(folio, pageout, &folio_list); huge_unlock: spin_unlock(ptl); if (pageout) @@ -502,9 +518,7 @@ static int madvise_lru_pmd_entry(pmd_t *pmd, unsigned long addr, if (nr < folio_nr_pages(folio)) { int err; - if (folio_maybe_mapped_shared(folio)) - continue; - if (pageout_anon_only_filter && !folio_test_anon(folio)) + if (madvise_lru_folio_is_filtered(folio, pageout_anon_only)) continue; if (!folio_trylock(folio)) continue; @@ -537,7 +551,7 @@ static int madvise_lru_pmd_entry(pmd_t *pmd, unsigned long addr, folio_mapcount(folio) != folio_nr_pages(folio)) continue; - if (pageout_anon_only_filter && !folio_test_anon(folio)) + if (pageout_anon_only && !folio_test_anon(folio)) continue; if (!pageout && pte_young(ptent)) { @@ -546,25 +560,7 @@ static int madvise_lru_pmd_entry(pmd_t *pmd, unsigned long addr, tlb_remove_tlb_entries(tlb, pte, nr, addr); } - /* - * We are deactivating a folio for accelerating reclaiming. - * VM couldn't reclaim the folio unless we clear PG_young. - * As a side effect, it makes confuse idle-page tracking - * because they will miss recent referenced history. - */ - folio_clear_referenced(folio); - folio_test_clear_young(folio); - if (folio_test_active(folio)) - folio_set_workingset(folio); - if (pageout) { - if (folio_isolate_lru(folio)) { - if (folio_test_unevictable(folio)) - folio_putback_lru(folio); - else - list_add(&folio->lru, &folio_list); - } - } else - folio_deactivate(folio); + madvise_lru_folio(folio, pageout, &folio_list); } out: @@ -651,8 +647,8 @@ static long madvise_pageout(struct madvise_behavior *madv_behavior) * owner nor write capable of the file. We allow private file mappings * further to pageout dirty anon pages. */ - if (!vma_is_anonymous(vma) && (!can_do_file_pageout(vma) && - (vma->vm_flags & VM_MAYSHARE))) + if (!vma_is_anonymous(vma) && !can_do_file_pageout(vma) && + (vma->vm_flags & VM_MAYSHARE)) return 0; lru_add_drain(); -- 2.53.0-Meta