From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794585959; b=AbbThwSqYdmKPKKgxB+uwL4oTKO+RBhzYIhyvf8i2cWn0snEg2Vx5ZQ5u1nsosXQ+R9O j1E+qu4UfKq9Ue4FWt0vR2dqniPZqrHHGwIBaCG1jhw8Jj1yqsDlid6FB0TJn4MhHL8mF 6JJZFspj4GTyGp4k30dEfSZkr4AfpypMMtqG0NawzLUKLJFFyVsnZRzKooYDHTrllkyKg /slEl/VgDQVugiC3rXCyZNrykNODCKIanTZpkxWAwSFiYHuogcaAGfx7iX/fTKpyjI/77 EF6/T9Mr0ZAawfVhSSzb8ufr5mfau8ZtkMJZYn0gQ06u/UIl1tLTHerL1/0Z/tnxSeg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794585959; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=jJnxqNEc9Ip+ieCE2hZ8ZyBHA+FG9mGwP6YvbqQElT8=; b=SNs49PgOrCPvLqeFVLKDp51IXBB8l6D9Cb5b9eHKyIcpZC8pcIJOAY50YayQnQem1PE5 Gx8+EPRRNRM1ic6H8meUXy0xCqq/1cqSFnC11uAFmdE+bwBn2dh173oSUXdPhSgz4wEzW 3ZsRoVrUPy+FqUB1iaHaZHsbxDJb1fnh4wDelrZg3skaN82zRgQm62ilmO6C6GMPpyj0Y VNka0DgxBPxuDItUxGp+wYR53j2R78+0f8Lb81kYYFU1GDaRy6gRJ/CopaQvr8WpmQRof DMZxXoHeWQ8ZFbLIZz0ImKoJZFrwlxCrxQVw6lvpKALIm47OyftzNn1r3VQdA8KKi3Q== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=qIAhmztr; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1F384606A896; Fri, 13 Nov 2026 16:05:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=qIAhmztr Received: by smtp.kernel.org (Postfix) with ESMTPSA id B707C1F000C6; Fri, 13 Nov 2026 16:05:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794585959; bh=jJnxqNEc9Ip+ieCE2hZ8ZyBHA+FG9mGwP6YvbqQElT8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=qIAhmztrfgrN0bGFxDDnzcgene0AQ8cZAuBMkrW76Add5tnmPDANjNPohMUCCE2xd Fddt/V4sp9MrUq3R3ns1RUxW3GS0MwDd22HKuZy7JiqhQ3GJ8lB+2/YTfBc3544nVC Jm4Ddv7ih1WPRVgI5SZHwdeciuuFLlOiyF5rrCa4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Kairui Song , Andrew Morton , Baolin Wang , Baoquan He , Barry Song , Ridong Chen , Axel Rasmussen , Chris Li , "David Hildenbrand (Arm)" , Johannes Weiner , Kairui Song , "Liam R. Howlett" , Lian Wang , Lorenzo Stoakes , Michal Hocko , Muchun Song , Qi Zheng , Roman Gushchin , Shakeel Butt , Vlastimil Babka , Wei Xu , Yuanchu Xie , Yu Zhao , Zi Yan , Sasha Levin Subject: [PATCH 7.3 504/507] mm/mglru: use explicit tier range in read_ctrl_pos() Date: Fri, 13 Nov 2026 10:53:28 -0500 Message-ID: <20261113153814.205346845@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153753.358973689@linuxfoundation.org> References: <20261113153753.358973689@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kairui Song [ Upstream commit c1d0e799321c817a22eab2abf2485250cffad7b4 ] read_ctrl_pos() encodes the tier range in a single "tier" parameter via "tier % MAX_NR_TIERS" as the start and "min(tier, MAX_NR_TIERS-1)" as the end. This is hard to follow, maintain, or extend. Tier values 0..3 select a single tier, while tier == MAX_NR_TIERS selects the full range. Replace it with explicit (tier_min, tier_max) parameters using a closed [tier_min, tier_max] interval, and add LRU_TIER_MIN and LRU_TIER_MAX for the tier bounds. The call sites now become self-documenting: - get_tier_idx: (LRU_TIER_MIN, LRU_TIER_MIN) for the first tier, (tier, tier) for each subsequent tier - get_type_to_scan: (LRU_TIER_MIN, LRU_TIER_MAX) for the full range No functional change. Link: https://lore.kernel.org/20260906-mglru-flags-cleanup-v6-5-9aacbd77d4ca@tencent.com Signed-off-by: Kairui Song Signed-off-by: Andrew Morton Reviewed-by: Baolin Wang Reviewed-by: Baoquan He Reviewed-by: Barry Song Reviewed-by: Ridong Chen Cc: Axel Rasmussen Cc: Chris Li Cc: David Hildenbrand (Arm) Cc: Johannes Weiner Cc: Kairui Song Cc: Liam R. Howlett Cc: Lian Wang Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Muchun Song Cc: Qi Zheng Cc: Roman Gushchin Cc: Shakeel Butt Cc: Vlastimil Babka Cc: Wei Xu Cc: Yuanchu Xie Cc: Yu Zhao Cc: Zi Yan Stable-dep-of: ca6e32f3f424 ("mm/vmscan: avoid false-positive -Wuninitialized warning, again") Signed-off-by: Sasha Levin --- include/linux/mmzone.h | 2 ++ mm/vmscan.c | 18 ++++++++++-------- 2 files changed, 12 insertions(+), 8 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 94f9c3ff54160..da8dd04fb462a 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -492,6 +492,8 @@ enum lruvec_flags { * folio->flags, masked by LRU_REFS_MASK. */ #define MAX_NR_TIERS 4U +#define LRU_TIER_MIN 0U +#define LRU_TIER_MAX (MAX_NR_TIERS - 1) #ifndef __GENERATING_BOUNDS_H diff --git a/mm/vmscan.c b/mm/vmscan.c index 963cdd67039d1..8ec8fdede5dd8 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3194,8 +3194,8 @@ struct ctrl_pos { int gain; }; -static void read_ctrl_pos(struct lruvec *lruvec, int type, int tier, int gain, - struct ctrl_pos *pos) +static void read_ctrl_pos(struct lruvec *lruvec, int type, int tier_min, + int tier_max, int gain, struct ctrl_pos *pos) { int i; struct lru_gen_folio *lrugen = &lruvec->lrugen; @@ -3204,7 +3204,7 @@ static void read_ctrl_pos(struct lruvec *lruvec, int type, int tier, int gain, pos->gain = gain; pos->refaulted = pos->total = 0; - for (i = tier % MAX_NR_TIERS; i <= min(tier, MAX_NR_TIERS - 1); i++) { + for (i = tier_min; i <= tier_max; i++) { pos->refaulted += lrugen->avg_refaulted[type][i] + atomic_long_read(&lrugen->refaulted[hist][type][i]); pos->total += lrugen->avg_total[type][i] + @@ -4808,9 +4808,9 @@ static int get_tier_idx(struct lruvec *lruvec, int type) * This value is chosen because any other tier would have at least twice * as many refaults as the first tier. */ - read_ctrl_pos(lruvec, type, 0, 2, &sp); - for (tier = 1; tier < MAX_NR_TIERS; tier++) { - read_ctrl_pos(lruvec, type, tier, 3, &pv); + read_ctrl_pos(lruvec, type, LRU_TIER_MIN, LRU_TIER_MIN, 2, &sp); + for (tier = LRU_TIER_MIN + 1; tier <= LRU_TIER_MAX; tier++) { + read_ctrl_pos(lruvec, type, tier, tier, 3, &pv); if (!positive_ctrl_err(&sp, &pv)) break; } @@ -4831,8 +4831,10 @@ static int get_type_to_scan(struct lruvec *lruvec, int swappiness) * Compare the sum of all tiers of anon with that of file to determine * which type to scan. */ - read_ctrl_pos(lruvec, LRU_GEN_ANON, MAX_NR_TIERS, swappiness, &sp); - read_ctrl_pos(lruvec, LRU_GEN_FILE, MAX_NR_TIERS, MAX_SWAPPINESS - swappiness, &pv); + read_ctrl_pos(lruvec, LRU_GEN_ANON, LRU_TIER_MIN, LRU_TIER_MAX, + swappiness, &sp); + read_ctrl_pos(lruvec, LRU_GEN_FILE, LRU_TIER_MIN, LRU_TIER_MAX, + MAX_SWAPPINESS - swappiness, &pv); return positive_ctrl_err(&sp, &pv); } -- 2.53.0