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 45DC01AD41F; Mon, 23 Dec 2024 16:09:05 +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=1734970146; cv=none; b=NvYKrMtZzUrpjoibCF5Vx14DHRuvHsqnbRTnk+vxE4QMPA9C/Z6I33fo8pXuFarx9/DC7krchBVhAb8OIDZcOwd0qNyKvD8V7oVSzrx341T/Wiwni14AD+kGJ1nhzeyNDqPh6qYDCD0NVLHJxGl8afFpiav2J5Np5Vvf1pQv+oA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734970146; c=relaxed/simple; bh=DztSW4tuK+jZUd5XqJ77zciMSgB6KR3YawOXRJwqm8s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ucbIpNbhN0LDob+BPbcpXMvw5OQPrwXQdnVrewhKmG2MiIMXofufu8KkkR05UI+iyt3UJguzeMNSU1rI2P58ojTNgzkfk/B8tvJ/ic0YUoPYd0AhgkMQDfVMgfmY/7B8RCY3TWAx0VoduYH3NgxYedzAIaiQC7D/Eu1DKu2M7ho= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ER1ZCYbP; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ER1ZCYbP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 39524C4CED3; Mon, 23 Dec 2024 16:09:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1734970145; bh=DztSW4tuK+jZUd5XqJ77zciMSgB6KR3YawOXRJwqm8s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ER1ZCYbPBMA/q2KXi+9/3jP5+FNOQyE/7Qh0CDJUoCQoqYUiwh8r1NLutmklaf6wR zNJ8QAZLkLqTu7nD21rPWHWT1YGLJre83n9JgYs9LAOqkoowtdUWJPKQzVtq1rRGuF /ua6S2tjpkm/MLo8lf92TPVKaE4mkWMKU51iV340= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, David Hildenbrand , Usama Arif , Johannes Weiner , Roman Gushchin , Barry Song , Domenico Cerasuolo , Jonathan Corbet , Matthew Wilcox , "Mike Rapoport (Microsoft)" , Nico Pache , Rik van Riel , Ryan Roberts , Shakeel Butt , Yu Zhao , Andrew Morton Subject: [PATCH 6.12 159/160] mm: convert partially_mapped set/clear operations to be atomic Date: Mon, 23 Dec 2024 16:59:30 +0100 Message-ID: <20241223155414.961764620@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241223155408.598780301@linuxfoundation.org> References: <20241223155408.598780301@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Usama Arif commit 42b2eb69835b0fda797f70eb5b4fc213dbe3a7ea upstream. Other page flags in the 2nd page, like PG_hwpoison and PG_anon_exclusive can get modified concurrently. Changes to other page flags might be lost if they are happening at the same time as non-atomic partially_mapped operations. Hence, make partially_mapped operations atomic. Link: https://lkml.kernel.org/r/20241212183351.1345389-1-usamaarif642@gmail.com Fixes: 8422acdc97ed ("mm: introduce a pageflag for partially mapped folios") Reported-by: David Hildenbrand Link: https://lore.kernel.org/all/e53b04ad-1827-43a2-a1ab-864c7efecf6e@redhat.com/ Signed-off-by: Usama Arif Acked-by: David Hildenbrand Acked-by: Johannes Weiner Acked-by: Roman Gushchin Cc: Barry Song Cc: Domenico Cerasuolo Cc: Jonathan Corbet Cc: Matthew Wilcox Cc: Mike Rapoport (Microsoft) Cc: Nico Pache Cc: Rik van Riel Cc: Ryan Roberts Cc: Shakeel Butt Cc: Yu Zhao Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- include/linux/page-flags.h | 12 ++---------- mm/huge_memory.c | 8 ++++---- 2 files changed, 6 insertions(+), 14 deletions(-) --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -860,18 +860,10 @@ static inline void ClearPageCompound(str ClearPageHead(page); } FOLIO_FLAG(large_rmappable, FOLIO_SECOND_PAGE) -FOLIO_TEST_FLAG(partially_mapped, FOLIO_SECOND_PAGE) -/* - * PG_partially_mapped is protected by deferred_split split_queue_lock, - * so its safe to use non-atomic set/clear. - */ -__FOLIO_SET_FLAG(partially_mapped, FOLIO_SECOND_PAGE) -__FOLIO_CLEAR_FLAG(partially_mapped, FOLIO_SECOND_PAGE) +FOLIO_FLAG(partially_mapped, FOLIO_SECOND_PAGE) #else FOLIO_FLAG_FALSE(large_rmappable) -FOLIO_TEST_FLAG_FALSE(partially_mapped) -__FOLIO_SET_FLAG_NOOP(partially_mapped) -__FOLIO_CLEAR_FLAG_NOOP(partially_mapped) +FOLIO_FLAG_FALSE(partially_mapped) #endif #define PG_head_mask ((1UL << PG_head)) --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3503,7 +3503,7 @@ int split_huge_page_to_list_to_order(str !list_empty(&folio->_deferred_list)) { ds_queue->split_queue_len--; if (folio_test_partially_mapped(folio)) { - __folio_clear_partially_mapped(folio); + folio_clear_partially_mapped(folio); mod_mthp_stat(folio_order(folio), MTHP_STAT_NR_ANON_PARTIALLY_MAPPED, -1); } @@ -3615,7 +3615,7 @@ bool __folio_unqueue_deferred_split(stru if (!list_empty(&folio->_deferred_list)) { ds_queue->split_queue_len--; if (folio_test_partially_mapped(folio)) { - __folio_clear_partially_mapped(folio); + folio_clear_partially_mapped(folio); mod_mthp_stat(folio_order(folio), MTHP_STAT_NR_ANON_PARTIALLY_MAPPED, -1); } @@ -3659,7 +3659,7 @@ void deferred_split_folio(struct folio * spin_lock_irqsave(&ds_queue->split_queue_lock, flags); if (partially_mapped) { if (!folio_test_partially_mapped(folio)) { - __folio_set_partially_mapped(folio); + folio_set_partially_mapped(folio); if (folio_test_pmd_mappable(folio)) count_vm_event(THP_DEFERRED_SPLIT_PAGE); count_mthp_stat(folio_order(folio), MTHP_STAT_SPLIT_DEFERRED); @@ -3752,7 +3752,7 @@ static unsigned long deferred_split_scan } else { /* We lost race with folio_put() */ if (folio_test_partially_mapped(folio)) { - __folio_clear_partially_mapped(folio); + folio_clear_partially_mapped(folio); mod_mthp_stat(folio_order(folio), MTHP_STAT_NR_ANON_PARTIALLY_MAPPED, -1); }