From nobody Thu Apr 2 00:09:38 2026 Received: from out-177.mta0.migadu.com (out-177.mta0.migadu.com [91.218.175.177]) (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 0398A39F196 for ; Thu, 5 Mar 2026 11:58:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.177 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772711940; cv=none; b=g/zyIkJM2M9Zf6dJEwOZsQ3YUaZenjk9bgtBIzpAUBS4TB60xoPEc4gv1Gw7sb/VEXzw1rWbSQfl78ETitMklnecAbNONr4s5m9x9TbSmPElmbG1rrFDZ47qgylBAfN4pLjOfTwXspR3sGI99BvWFwmbURX6qeou2b+ImdYaYi0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772711940; c=relaxed/simple; bh=Sg7X0J2LeOj21kGyyAuviahyCnjetwqckops/SwYF7U=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=k9w0ns4f9B2QEeyeJugUfuJuSZEnJ2t0jSU11aR2jxJ45OQJk2CEEjl8TagYuRiatQ0g0Fbl23FyAGmgBzhz6uOdiqdxsyV3X/MSjES3EsWTI+c0FnvoDjY7H5GZWO5QCjXy/JrVnuMfsFp8qCrsaaoFZKDTGviGH7ut/q1BrEI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=BOcfMfGt; arc=none smtp.client-ip=91.218.175.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="BOcfMfGt" 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=1772711937; 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=Ih1p6IEUWMwvOImSKCL1YcoSFVupYh3GoMOZwrQGBdQ=; b=BOcfMfGtjpHcZp+xS/IpT3JULkLv02uZSYMCkCq8bDAyt4Jvy92uC0aTckuxqn3xx3Jxbb q/M0pn2SWVc7gCp+kU8JZd+USDTs48XoIopK3xpPraNBcil60WNqxgue3ZE0S/NnoqLuR+ zXFJzorToXtaCX16OVcQD6Gtc39QfHA= 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, bhe@redhat.com, usamaarif642@gmail.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Qi Zheng Subject: [PATCH v6 27/33] mm: memcontrol: refactor memcg_reparent_objcgs() Date: Thu, 5 Mar 2026 19:52:45 +0800 Message-ID: <2e5696db1993e593a51004c1dacedbc261689629.1772711148.git.zhengqi.arch@bytedance.com> In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" From: Qi Zheng Refactor the memcg_reparent_objcgs() to facilitate subsequent reparenting LRU folios here. Signed-off-by: Qi Zheng Acked-by: Johannes Weiner Acked-by: Shakeel Butt Reviewed-by: Harry Yoo Reviewed-by: Muchun Song --- mm/memcontrol.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 49a076b7c2e42..5929e397c3c31 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -209,15 +209,12 @@ static struct obj_cgroup *obj_cgroup_alloc(void) return objcg; } =20 -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 =3D parent_mem_cgroup(memcg); =20 objcg =3D 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. */ @@ -226,7 +223,29 @@ static void memcg_reparent_objcgs(struct mem_cgroup *m= emcg) /* 3) Move already reparented objcgs to the parent's list */ list_splice(&memcg->objcg_list, &parent->objcg_list); =20 + return objcg; +} + +static inline void reparent_locks(struct mem_cgroup *memcg, struct mem_cgr= oup *parent) +{ + spin_lock_irq(&objcg_lock); +} + +static inline void reparent_unlocks(struct mem_cgroup *memcg, struct mem_c= group *parent) +{ spin_unlock_irq(&objcg_lock); +} + +static void memcg_reparent_objcgs(struct mem_cgroup *memcg) +{ + struct obj_cgroup *objcg; + struct mem_cgroup *parent =3D parent_mem_cgroup(memcg); + + reparent_locks(memcg, parent); + + objcg =3D __memcg_reparent_objcgs(memcg, parent); + + reparent_unlocks(memcg, parent); =20 percpu_ref_kill(&objcg->refcnt); } --=20 2.20.1