From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qt1-f178.google.com (mail-qt1-f178.google.com [209.85.160.178]) (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 2F6733093B5 for ; Wed, 17 Dec 2025 22:36:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.178 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766010995; cv=none; b=C8y1WdO4+FHzvl4mVLOffC+VvKrCBJovkdKGaPVbQuYWtfL7gyl43b5fDcDGGhDRY8SwxmmOmcdxdG2X/AIzvEYARBmuOKLa+VEMhCyNKBIUoBRNmyJG+U6xqKXGWzLUysacLss2wH1UXd7Z5QblqcZ5Xc1u9OI/SO0zbaglPl0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766010995; c=relaxed/simple; bh=ZlT3KqTofwvBhqMe18ZKfZ4B3GbTBwIPlOKEwMBXdOo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=B8wwJj6j+++b4zeA7utqjGwlnFh9Dt2hZiICyTdzeiGQlfAqU8+sXTetFNzPcMaj0loycdpfBDnUrwBoUktfkGlvAUXGk6sJJg78aWxyixhcyBdf1C9LeNYWmPttZsuZjHQgCgJuK2z8xP3PmIRekMznXBZY5uuaj3vv7Xg9VPg= 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=cywIUXl1; arc=none smtp.client-ip=209.85.160.178 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="cywIUXl1" Received: by mail-qt1-f178.google.com with SMTP id d75a77b69052e-4ed82ee9e57so31001cf.0 for ; Wed, 17 Dec 2025 14:36:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg.org; s=google; t=1766010991; x=1766615791; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=kR/+xgf6Jhz+E5StwKcRK1JFVZohgr4tToC9Isegfuo=; b=cywIUXl1d+0/ikwRqhwvJtnNsFXsCVQzp1s+Ab8De2GklVPa3KvBj0421B78pa4NEV nZjAd51OxqyheOnHMineFg3nmqM8jQnyOT00Jksf1Eh9fJZYCB3Ley3MwkiI9S3YriZ/ //0GPu2pSORy+WaDv5NOIgc69l649t3ryWbdpR4ROmW6+JQFqp5fKrca28n1i8WduJrG OPckdvp7ImGWK91rA72kOR5Nq39XUowhcGYo4OEyojKArPAlHQrBQaumCjcCX+VYdWvq AEnUrMWDiXFzqPy1QuR/SMqEKucLwmCiIVzOnfH7Gm7qpJ/NRhSnkLsmPsmttuidxl3q yH3w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1766010991; x=1766615791; h=in-reply-to:content-disposition: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; bh=kR/+xgf6Jhz+E5StwKcRK1JFVZohgr4tToC9Isegfuo=; b=VxVakPCCajZDxpSg9Tp/lLOKWYynaZcnTO8q28axKdQO6Ehw6LJpJhP2MkZU5KnQ1v iap16SbUp2xl+iUu0+OTAKrrMHGYzwSbLZtOD4zKZ0IzAKRTd8ILucGA+qm+IivIivTL pXLDGBsEupSOZtFqCZiw6RqorfK4wx86vAvmkDQ/peKcEosOvhBUOedjwbgjpUzEUCyJ eWrBHldm6OTKEA6ZDBqaCMxwnooD6PTx/5oC/QbPuJ4hhraosGey8RsHDCzwFNkzfPAK bNo/czFA5ICmMdGW+NfLjlRANQLgsa+fldoD2UO6AB+8EnVlNZgpIU9l3Lcju5thm6mJ HOdw== X-Forwarded-Encrypted: i=1; AJvYcCU/cleLYSXr8rJ6u4uL9kHbLzvMZfE8s8vZLA9Eb22oCfXUFwoyr0pOTo/ujqH9SjX1sLGMRPZB37kg5sI=@vger.kernel.org X-Gm-Message-State: AOJu0YxsnJsvSMJARm3g6cKDlKVtt44UdjglhzIYNorInTHCJ+cprMZX 9oyRGD88C1khWYdDQRyTugS0h4qrMPuvYQqQ0jXa+oWCtm+rXapahqWSJvyqGu+4zOw= X-Gm-Gg: AY/fxX4mu5oymQXGNgaK7juwfTeBfzLvrD2IfjoqjFyxyoYx96fElDAwlqWsBHR3c6S kinrru5t+fBnw+NkzvVf1opddVw4d0zgyGci/SIGkH+VDb62O1FVe1LJKItoxjb+oUm0eLDEshW tgKsoiybD4OJTcGSMeEg7afqjEgGKHElLHedxGGhihRo1tA7oAGRiMNiAXpfnjyLosrGUSkS5t0 cVSJ1C1yduf8VV2mipmtk8vh4ov0IBJIM3idA4A8orKhZkcfzR143dQH24AnzJUq2wbFL7HumtS IN6v40M7ArY8BbKlllNsxMWyaXd2cGtSu6Yru19hGEU3HVDXIqHiLAJcO7+V0zSYV4w+C0X5+da jjPSBjPiZ85q9hmA9z0N9+Fa4/LZ9tdbZgb6PleCoKY2t2SOACkWLUF6cGu2h6kk7yXJeq5BKL2 GzWwcjwZToAw== X-Google-Smtp-Source: AGHT+IFEnoIqNTzn/beBrrTTMm5NCOBdf6XqjRvcyNax+rsawQ6zsZEDQLLD5Cw+412x47E2IhWIYQ== X-Received: by 2002:a05:622a:4d89:b0:4ec:ee2e:1c20 with SMTP id d75a77b69052e-4f1d05a9294mr251307421cf.47.1766010991640; Wed, 17 Dec 2025 14:36:31 -0800 (PST) Received: from localhost ([2603:7000:c01:2716:929a:4aff:fe16:c778]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-88c5dc728afsm4765666d6.12.2025.12.17.14.36.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Dec 2025 14:36:30 -0800 (PST) Date: Wed, 17 Dec 2025 17:36:30 -0500 From: Johannes Weiner To: Qi Zheng Cc: 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, 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, linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Muchun Song , Qi Zheng Subject: Re: [PATCH v2 22/28] mm: workingset: prevent lruvec release in workingset_activation() Message-ID: References: <195a8cb47b90e48cd1ec6cb93bc33a8e794847f6.1765956026.git.zhengqi.arch@bytedance.com> 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: <195a8cb47b90e48cd1ec6cb93bc33a8e794847f6.1765956026.git.zhengqi.arch@bytedance.com> On Wed, Dec 17, 2025 at 03:27:46PM +0800, Qi Zheng wrote: > From: Muchun Song > > In the near future, a folio will no longer pin its corresponding > memory cgroup. So an lruvec returned by folio_lruvec() could be > released without the rcu read lock or a reference to its memory > cgroup. > > In the current patch, the rcu read lock is employed to safeguard > against the release of the lruvec in workingset_activation(). > > This serves as a preparatory measure for the reparenting of the > LRU pages. > > Signed-off-by: Muchun Song > Signed-off-by: Qi Zheng > Reviewed-by: Harry Yoo Acked-by: Johannes Weiner