From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk1-f173.google.com (mail-qk1-f173.google.com [209.85.222.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 52DE34218AA for ; Fri, 10 Jul 2026 11:50:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783684225; cv=none; b=f/PbMxaVUPHmGG0lBsWbf0xzMz51OBn48mYsl71ffed5+w4UsCUzYsZe0sSwfFHcbyV+6JxVO/yckK0PDmu68ylYN0FmHFXxvvDPH3dPFtrNE0oveaNsI2Kp2RMYOntn6bCvh2Nle/KnzHMx7lIn0y9oswOGiZNVMieU+rc0O/s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783684225; c=relaxed/simple; bh=VTQ5/pM0OAZjucDkuAXhdWo24CpuZaBSbKTGjrZXldo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Ik3OKooH8PRaEC/wX9w57SkZ3VxcQ4zdxdlTMMhLs6KK3GXmGylrubBg1PIziQM3h6HEDBGDbQjOpJZxQCJx/giAYtvuf+vOPvFj9QNit508ZVwShNhNKvZwJq6RiFUB4o9LwVvSgZ39T2T1YVH2p8y16N09kQyMMmtH50BXZMI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=cmpxchg.org; spf=pass smtp.mailfrom=cmpxchg.org; dkim=pass (2048-bit key) header.d=cmpxchg.org header.i=@cmpxchg.org header.b=bvWwRRF+; arc=none smtp.client-ip=209.85.222.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=cmpxchg.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=cmpxchg.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=cmpxchg.org header.i=@cmpxchg.org header.b="bvWwRRF+" Received: by mail-qk1-f173.google.com with SMTP id af79cd13be357-92e57a753f9so61256385a.2 for ; Fri, 10 Jul 2026 04:50:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg.org; s=google; t=1783684211; x=1784289011; darn=vger.kernel.org; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=O1cv839pt6gMzmGWDQWXXSzIxfFZGm2rebUfeK7nSPU=; b=bvWwRRF+PuNpa131cg97MZ1Ahv6x6iPA+32rduWdSbj0OTipCKHeLxLLJqoCJ8LDRK UOPBHy0PLdH5e7t8COeSBdvR3N0vOdgmOU/0WOEh/svWjBg3CyPtWVDUCLe54xxxuRJz 1wm/AG0sxCH5KY1lxBOZSyn+mvaBfGzFaU49/PBRO6Ptx3UfTfAFD6L19nNL05AscDjk B67rS2m9dRVmpxEq5WAKd5Ln0yGST96lMUHEpztocGGSAeusYlnHtyAnt8cBYzSqYOkL h6QZ2WKt/Sr4CQkjtnIyxuBCidLxKsGkFcMUOhKYaqP24eYSu9gzpFymewX0/SY+j/kx lCZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783684211; x=1784289011; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=O1cv839pt6gMzmGWDQWXXSzIxfFZGm2rebUfeK7nSPU=; b=ENQfIdv+Vkr2YIOMhgftMxP/QYU0qwLU05nyLvrETQxaaH36HbL1TbAtqRqGzs+GQF fa8Id2ZoVh2mKYVXvVCBynjvnw9b2Yx9QvpI19jQ05MFL3roMi2m63ZVAB69jt9e5ZFB 9NkExl8NPVGOmcrUyL98VthNLrf7/HvuE2TwUik/vWLRELrm9zNfS9MuSIkPTnfj3tQf Zy6YF+FFcqzdmpZCvJCQrbflBn22jFg/4+W7mr1b8UvA7PljfWn/rjB8b051Gms2dWTv icTIiWXWJGeXbGhj40/7hGDsLg+YLAFDXiHtEbCqhAGMb/4zABZd5q9yuY+aLO6f0gEA ZHvQ== X-Forwarded-Encrypted: i=1; AHgh+RoZCjHI/9HBIeKyKmsCtLCqC6UKgWfxRhpnXMLMMVeaoWD5ExfonPrmrljZ6BtsBb+RJ3+1WIL0mhb0/1w=@vger.kernel.org X-Gm-Message-State: AOJu0Yxb0GguKnqSnKSsQyNGLUTyWzmXUml5jUIW2mSkJvyBeMWSxULx hXWOdtoEvkLUV1zUbXRvq+kXTttXQoOm6kpRoOjz+iCqJ9fplt7JKxCYpw4YaJnqAfw= X-Gm-Gg: AfdE7ck8gYHAYFLNsmZ3ETFWw9ObwQ9l7TUvmqHhuW7H/FIM0kholznVz6GZMMCN4kg /jnJ+sXdix2H0R5CQMgH8VIV1KOdDzGmfRJb5WLz2GTDwGOdoddYfWCkfqSVokPPBeawmOAHPrR WVF2isyvoCpWhyhuwvqmQ8EgWupegaA6MnFn2jgFlVFAwUbYTXiplSVGsD9TmC2AIuCHhUSs9Y9 GEfcEU4cb8p+4C62pWvV1bj6rBER4Js9Wv/IyWkY02GPU9/OkfhozXytDZJEK59pWllq3HRrh+S AnUZnT2++Crr7IugsQiz+DR8bPfAaks9ie5A5/f69fTYFZDcS32lNkr8g26qVjKnHk0r8+M9uuB jpdIZeSmTuRc720WOhbjyFZi4upPDI2r9QIzxSVsdz5gxb1VCaqR8b6HHN6aoJ2GTBa0rOtg7qq jiHSCOF45lwSs= X-Received: by 2002:a05:620a:8082:b0:92e:c117:9eaa with SMTP id af79cd13be357-92ecf908aadmr1243149185a.88.1783684211285; Fri, 10 Jul 2026 04:50:11 -0700 (PDT) Received: from localhost ([2603:7001:f100:500:365a:60ff:fe62:ff29]) by smtp.gmail.com with ESMTPSA id af79cd13be357-92ee5b4a0cbsm176929585a.5.2026.07.10.04.50.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Jul 2026 04:50:10 -0700 (PDT) Date: Fri, 10 Jul 2026 07:50:09 -0400 From: Johannes Weiner To: Qi Zheng Cc: Harry Yoo , Usama Arif , akpm@linux-foundation.org, david@kernel.org, kasong@tencent.com, shakeel.butt@linux.dev, baohua@kernel.org, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, muchun.song@linux.dev, peiyang_he@smail.nju.edu.cn, mhocko@kernel.org, roman.gushchin@linux.dev, ljs@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Qi Zheng , stable@vger.kernel.org Subject: Re: [PATCH v4] mm: mglru: fix stale batch updates after memcg reparenting Message-ID: References: <20260701145736.3785016-1-usama.arif@linux.dev> <2fb5ce53-666b-4b0a-a4ad-2b3a28c54768@kernel.org> <843f6d0d-e893-43ef-9cb3-1df21fb64b8d@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <843f6d0d-e893-43ef-9cb3-1df21fb64b8d@linux.dev> On Fri, Jul 10, 2026 at 02:19:15PM +0800, Qi Zheng wrote: > On 7/10/26 9:51 AM, Johannes Weiner wrote: > > On Thu, Jul 02, 2026 at 09:38:41AM +0800, Qi Zheng wrote: > >> On 7/1/26 11:59 PM, Johannes Weiner wrote: > >>> lruvec_live_lock_irq()? > >> > >> But lruvec_lock_irq() grabs the rcu lock too. :( > > > > Yes, but it's self-explanatory if you put it with those definitions: > > > > static inline void lruvec_lock_irq(struct lruvec *lruvec) > > { > > rcu_read_lock(); > > spin_lock_irq(&lruvec->lru_lock); > > } > > > > static struct lruvec *lruvec_live_lock_irq(struct lruvec *lruvec) > > { > > struct mem_cgroup *memcg = lruvec_memcg(lruvec); > > > > rcu_read_lock(); > > while (unlikely(memcg && css_is_dying(&memcg->css))) { > > memcg = parent_mem_cgroup(memcg); > > lruvec = mem_cgroup_lruvec(memcg, lruvec_pgdat(lruvec)); > > } > > spin_lock_irq(&lruvec->lru_lock); > > } > > All right, should the implementation for !CONFIG_MEMCG be placed here > too? Yes. You can just #ifdef, #else the function body itself. static struct lruvec *lruvec_live_lock_irq() { #ifdef CONFIG_MEMCG ... #else lruvec_lock_irq(lruvec); return lruvec; #endif } > Will send the v5. Thanks.