From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DD2FFD29FF1 for ; Wed, 14 Jan 2026 11:36:20 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4D7D76B00C3; Wed, 14 Jan 2026 06:36:20 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 482236B00C5; Wed, 14 Jan 2026 06:36:20 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 39B206B00C6; Wed, 14 Jan 2026 06:36:20 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 286CE6B00C3 for ; Wed, 14 Jan 2026 06:36:20 -0500 (EST) Received: from smtpin29.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id EAF3DB9A3A for ; Wed, 14 Jan 2026 11:36:19 +0000 (UTC) X-FDA: 84330366078.29.91B9FC5 Received: from out-178.mta0.migadu.com (out-178.mta0.migadu.com [91.218.175.178]) by imf25.hostedemail.com (Postfix) with ESMTP id 485BFA0005 for ; Wed, 14 Jan 2026 11:36:18 +0000 (UTC) Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=Q96h2Xw2; spf=pass (imf25.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.178 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1768390578; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=rCn71o4CGVG6ZCimcBHoYvDX6iNx84ttSjck4drbD9c=; b=8i32eDzDsMQJP22MCswPVc9M4LO3Hh41F0EFSvzYLxXOWNjbxW28c0wOEdC7ok7kI/M8PD Ri5H3MI5K7Le2jGesYPRXwDmtCCHx+UZaEp0v5y57z2mPjuyeirmB3wQc7Zhl2equbzFej cZ4ADnGbLfsvfImglRNaI4J1Qp0pVyY= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=Q96h2Xw2; spf=pass (imf25.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.178 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1768390578; a=rsa-sha256; cv=none; b=aSQUsE28YLWWmHODPc4FuiZIkXnHNmve69Io3yI5flnsKhIKsfm6TMXo+cCbwmFQBrMWi2 uAYXAzKvxRotXBdEqC9yDlB+x+IEteI+F24clsD7IWaW06emokZz/RXcXpBtGkM0DEvG98 6Rselti3F2iqIfx8cld86wGbZKEvlfk= 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=1768390576; 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=rCn71o4CGVG6ZCimcBHoYvDX6iNx84ttSjck4drbD9c=; b=Q96h2Xw2FW89SLH/7JvVfXdzJRpn9+6lVcUlq55C3OXjGlnp637HPE+22QxBSQ77rM7yha 3Sw67e034q/9edHVNRxG3QNikHhUw4iSAMurkyZnCcIiTfUHRWAE1njcGzgltkUpE6TFfq cGAVi5cmgo6AsI55+TYXghSBv9ZzWr8= 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, yosry.ahmed@linux.dev, 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, Qi Zheng Subject: [PATCH v3 27/30] mm: memcontrol: refactor memcg_reparent_objcgs() Date: Wed, 14 Jan 2026 19:32:54 +0800 Message-ID: <843e9537bf6b99cc7f19744a6f53b92338c96bfe.1768389889.git.zhengqi.arch@bytedance.com> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Stat-Signature: h49w5dh5kuzc4rn4shmf7frxu65ayf8t X-Rspam-User: X-Rspamd-Queue-Id: 485BFA0005 X-Rspamd-Server: rspam08 X-HE-Tag: 1768390578-59120 X-HE-Meta: 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 PMuRp5J8 q/D3DuUTiWlubsFkE+hN8QjqRZ072OA1iNGk7Zu2+gJXy52Lbfv3G/v/D/F9Kqn1Qo/E1hdKZgMC/7R8L+P+CNpWDq6p2g4ll/N02aORMfo2EbHGqmBv4GyXzFHEBOOKnC/ZAtvot3rrQ17ty3Xkl+fljof72DKSc7e3wIvi82eTV2naxJ0h2iHS00rF4YGWctsSe7t0zQXpAJsy/UxEytz4xngeCEOrNrTXGgqKLSUHqDyismMeUAtDLX3GxPVW3T5nkBbHkTwUVuVOQL3UeBjcbSGgxTxYuAvnYziZmTd8CAVOU2fgesIZdF59zTutuO5+wsWAFu0+DDKI= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Qi Zheng Refactor the memcg_reparent_objcgs() to facilitate subsequent reparenting LRU folios here. Signed-off-by: Qi Zheng Acked-by: Johannes Weiner --- mm/memcontrol.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index a1573600d4188..70583394f421f 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -208,15 +208,12 @@ static struct obj_cgroup *obj_cgroup_alloc(void) return objcg; } -static void memcg_reparent_objcgs(struct mem_cgroup *memcg) +static inline struct obj_cgroup *__memcg_reparent_objcgs(struct mem_cgroup *memcg, + struct mem_cgroup *parent) { struct obj_cgroup *objcg, *iter; - struct mem_cgroup *parent = parent_mem_cgroup(memcg); objcg = rcu_replace_pointer(memcg->objcg, NULL, true); - - spin_lock_irq(&objcg_lock); - /* 1) Ready to reparent active objcg. */ list_add(&objcg->list, &memcg->objcg_list); /* 2) Reparent active objcg and already reparented objcgs to parent. */ @@ -225,7 +222,29 @@ static void memcg_reparent_objcgs(struct mem_cgroup *memcg) /* 3) Move already reparented objcgs to the parent's list */ list_splice(&memcg->objcg_list, &parent->objcg_list); + return objcg; +} + +static inline void reparent_locks(struct mem_cgroup *memcg, struct mem_cgroup *parent) +{ + spin_lock_irq(&objcg_lock); +} + +static inline void reparent_unlocks(struct mem_cgroup *memcg, struct mem_cgroup *parent) +{ spin_unlock_irq(&objcg_lock); +} + +static void memcg_reparent_objcgs(struct mem_cgroup *memcg) +{ + struct obj_cgroup *objcg; + struct mem_cgroup *parent = parent_mem_cgroup(memcg); + + reparent_locks(memcg, parent); + + objcg = __memcg_reparent_objcgs(memcg, parent); + + reparent_unlocks(memcg, parent); percpu_ref_kill(&objcg->refcnt); } -- 2.20.1