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 EC1452580D7; Sat, 13 Sep 2025 20:09:24 +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=1757794165; cv=none; b=q/2sCH6X6JPZ2Zz3eJ3pIhfRBXBMazAVv/raB09OudLHh2zvIhPKrLT8ZvggQ1v3xFPz6J7RInbI9Ov1xP/TidLEmHmU8z2y/QRQlSWbd22mLRXtMamZk4xXukD9lNq/gFBD8G07YJPlvYnQQQiUG7am1z5U3ToFaumZM/cCNdQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757794165; c=relaxed/simple; bh=COvO7k8dn7JjYVZ2mOoF40umF684m9+HvsU3jTRHRGY=; h=Date:To:From:Subject:Message-Id; b=OMQTbe0gLB6VnWPK88sZSy5feHzwlpTblLs8qqLgXXsLoXAZ+GXmpp5F3dFZqTSPiL2K2DU7GD7XnfhRouyq+vKx0fNOU+oZ162wG968f5ccak/tLmFH7Pm1D2Cu6wayIEGMkydspIQgw9oj7XsFuSi9lWKfQgaskCOIWEERKUs= 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=yGPwsNn0; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="yGPwsNn0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A44E5C4CEEB; Sat, 13 Sep 2025 20:09:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1757794164; bh=COvO7k8dn7JjYVZ2mOoF40umF684m9+HvsU3jTRHRGY=; h=Date:To:From:Subject:From; b=yGPwsNn0VVUOen8kEiJ7jARZAfKUhAaRaGvIeMyKk/XzgxqU8yEF7N8vxAJ6oCM6T PHWK6Eo7hmS9QWXkg6mXV1bX+PalJ1I1AAdrW/epwkgKj5WOYY7+YStlYew9xtsM2X cSuIT0oHgxUsUJvSvvXHBCywDCD6c5Zfcs8ouaQg= Date: Sat, 13 Sep 2025 13:09:24 -0700 To: mm-commits@vger.kernel.org,yuzhao@google.com,yuanchu@google.com,yangge1116@126.com,willy@infradead.org,will@kernel.org,weixugc@google.com,vbabka@suse.cz,stable@vger.kernel.org,shivankg@amd.com,riel@surriel.com,peterx@redhat.com,lizhe.67@bytedance.com,koct9i@gmail.com,keirf@google.com,jhubbard@nvidia.com,jgg@ziepe.ca,hch@infradead.org,hannes@cmpxchg.org,david@redhat.com,chrisl@kernel.org,axelrasmussen@google.com,aneesh.kumar@kernel.org,hughd@google.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-hotfixes-stable] mm-revert-mm-gup-clear-the-lru-flag-of-a-page-before-adding-to-lru-batch.patch removed from -mm tree Message-Id: <20250913200924.A44E5C4CEEB@smtp.kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm: revert "mm/gup: clear the LRU flag of a page before adding to LRU batch" has been removed from the -mm tree. Its filename was mm-revert-mm-gup-clear-the-lru-flag-of-a-page-before-adding-to-lru-batch.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Hugh Dickins Subject: mm: revert "mm/gup: clear the LRU flag of a page before adding to LRU batch" Date: Mon, 8 Sep 2025 15:19:17 -0700 (PDT) This reverts commit 33dfe9204f29: now that collect_longterm_unpinnable_folios() is checking ref_count instead of lru, and mlock/munlock do not participate in the revised LRU flag clearing, those changes are misleading, and enlarge the window during which mlock/munlock may miss an mlock_count update. It is possible (I'd hesitate to claim probable) that the greater likelihood of missed mlock_count updates would explain the "Realtime threads delayed due to kcompactd0" observed on 6.12 in the Link below. If that is the case, this reversion will help; but a complete solution needs also a further patch, beyond the scope of this series. Included some 80-column cleanup around folio_batch_add_and_move(). The role of folio_test_clear_lru() (before taking per-memcg lru_lock) is questionable since 6.13 removed mem_cgroup_move_account() etc; but perhaps there are still some races which need it - not examined here. Link: https://lore.kernel.org/linux-mm/DU0PR01MB10385345F7153F334100981888259A@DU0PR01MB10385.eurprd01.prod.exchangelabs.com/ Link: https://lkml.kernel.org/r/05905d7b-ed14-68b1-79d8-bdec30367eba@google.com Signed-off-by: Hugh Dickins Acked-by: David Hildenbrand Cc: "Aneesh Kumar K.V" Cc: Axel Rasmussen Cc: Chris Li Cc: Christoph Hellwig Cc: Jason Gunthorpe Cc: Johannes Weiner Cc: John Hubbard Cc: Keir Fraser Cc: Konstantin Khlebnikov Cc: Li Zhe Cc: Matthew Wilcox (Oracle) Cc: Peter Xu Cc: Rik van Riel Cc: Shivank Garg Cc: Vlastimil Babka Cc: Wei Xu Cc: Will Deacon Cc: yangge Cc: Yuanchu Xie Cc: Yu Zhao Cc: Signed-off-by: Andrew Morton --- mm/swap.c | 50 ++++++++++++++++++++++++++------------------------ 1 file changed, 26 insertions(+), 24 deletions(-) --- a/mm/swap.c~mm-revert-mm-gup-clear-the-lru-flag-of-a-page-before-adding-to-lru-batch +++ a/mm/swap.c @@ -164,6 +164,10 @@ static void folio_batch_move_lru(struct for (i = 0; i < folio_batch_count(fbatch); i++) { struct folio *folio = fbatch->folios[i]; + /* block memcg migration while the folio moves between lru */ + if (move_fn != lru_add && !folio_test_clear_lru(folio)) + continue; + folio_lruvec_relock_irqsave(folio, &lruvec, &flags); move_fn(lruvec, folio); @@ -176,14 +180,10 @@ static void folio_batch_move_lru(struct } static void __folio_batch_add_and_move(struct folio_batch __percpu *fbatch, - struct folio *folio, move_fn_t move_fn, - bool on_lru, bool disable_irq) + struct folio *folio, move_fn_t move_fn, bool disable_irq) { unsigned long flags; - if (on_lru && !folio_test_clear_lru(folio)) - return; - folio_get(folio); if (disable_irq) @@ -191,8 +191,8 @@ static void __folio_batch_add_and_move(s else local_lock(&cpu_fbatches.lock); - if (!folio_batch_add(this_cpu_ptr(fbatch), folio) || folio_test_large(folio) || - lru_cache_disabled()) + if (!folio_batch_add(this_cpu_ptr(fbatch), folio) || + folio_test_large(folio) || lru_cache_disabled()) folio_batch_move_lru(this_cpu_ptr(fbatch), move_fn); if (disable_irq) @@ -201,13 +201,13 @@ static void __folio_batch_add_and_move(s local_unlock(&cpu_fbatches.lock); } -#define folio_batch_add_and_move(folio, op, on_lru) \ - __folio_batch_add_and_move( \ - &cpu_fbatches.op, \ - folio, \ - op, \ - on_lru, \ - offsetof(struct cpu_fbatches, op) >= offsetof(struct cpu_fbatches, lock_irq) \ +#define folio_batch_add_and_move(folio, op) \ + __folio_batch_add_and_move( \ + &cpu_fbatches.op, \ + folio, \ + op, \ + offsetof(struct cpu_fbatches, op) >= \ + offsetof(struct cpu_fbatches, lock_irq) \ ) static void lru_move_tail(struct lruvec *lruvec, struct folio *folio) @@ -231,10 +231,10 @@ static void lru_move_tail(struct lruvec void folio_rotate_reclaimable(struct folio *folio) { if (folio_test_locked(folio) || folio_test_dirty(folio) || - folio_test_unevictable(folio)) + folio_test_unevictable(folio) || !folio_test_lru(folio)) return; - folio_batch_add_and_move(folio, lru_move_tail, true); + folio_batch_add_and_move(folio, lru_move_tail); } void lru_note_cost_unlock_irq(struct lruvec *lruvec, bool file, @@ -328,10 +328,11 @@ static void folio_activate_drain(int cpu void folio_activate(struct folio *folio) { - if (folio_test_active(folio) || folio_test_unevictable(folio)) + if (folio_test_active(folio) || folio_test_unevictable(folio) || + !folio_test_lru(folio)) return; - folio_batch_add_and_move(folio, lru_activate, true); + folio_batch_add_and_move(folio, lru_activate); } #else @@ -507,7 +508,7 @@ void folio_add_lru(struct folio *folio) lru_gen_in_fault() && !(current->flags & PF_MEMALLOC)) folio_set_active(folio); - folio_batch_add_and_move(folio, lru_add, false); + folio_batch_add_and_move(folio, lru_add); } EXPORT_SYMBOL(folio_add_lru); @@ -685,13 +686,13 @@ void lru_add_drain_cpu(int cpu) void deactivate_file_folio(struct folio *folio) { /* Deactivating an unevictable folio will not accelerate reclaim */ - if (folio_test_unevictable(folio)) + if (folio_test_unevictable(folio) || !folio_test_lru(folio)) return; if (lru_gen_enabled() && lru_gen_clear_refs(folio)) return; - folio_batch_add_and_move(folio, lru_deactivate_file, true); + folio_batch_add_and_move(folio, lru_deactivate_file); } /* @@ -704,13 +705,13 @@ void deactivate_file_folio(struct folio */ void folio_deactivate(struct folio *folio) { - if (folio_test_unevictable(folio)) + if (folio_test_unevictable(folio) || !folio_test_lru(folio)) return; if (lru_gen_enabled() ? lru_gen_clear_refs(folio) : !folio_test_active(folio)) return; - folio_batch_add_and_move(folio, lru_deactivate, true); + folio_batch_add_and_move(folio, lru_deactivate); } /** @@ -723,10 +724,11 @@ void folio_deactivate(struct folio *foli void folio_mark_lazyfree(struct folio *folio) { if (!folio_test_anon(folio) || !folio_test_swapbacked(folio) || + !folio_test_lru(folio) || folio_test_swapcache(folio) || folio_test_unevictable(folio)) return; - folio_batch_add_and_move(folio, lru_lazyfree, true); + folio_batch_add_and_move(folio, lru_lazyfree); } void lru_add_drain(void) _ Patches currently in -mm which might be from hughd@google.com are mm-lru_add_drain_all-do-local-lru_add_drain-first.patch