From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f173.google.com (mail-pl1-f173.google.com [209.85.214.173]) (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 68D6E2F7468 for ; Fri, 5 Sep 2025 21:41:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757108465; cv=none; b=l6bL+XDq0QRegDCyRN6hu3NlZ4pxSWrSp46P1+EsaTeJ2v49I3yfwA3QQsbKVhgfWVN6UjKqqzgwziGZ8wsmLdxokgzhAljy/zSnK2f+epdPUSscko6dqh+z0v6W+5F3kb0wQvA6uu1gLQ/DKv/usp4/FvO6w1bDIDb+/CvhMho= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757108465; c=relaxed/simple; bh=EISgDghY/knXbNwDvDGK2KSaNFpugS1NjVBQvkSH1ok=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=pnrPfS2l7H121/K6vTHpZFeBWyphSpyfJ/xyAUTQX+MavblVe8s4ByNkK1jmn04qucGnzpNfZHMou9Aa1hso1nxRzFL5y5taB5cTy8vVETvsXswJfq+OWOWrcGgTkSlAeuOHprmin9Ql/RqutmVHm0lsoI1l3LL0VjBi9oqypo8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=FC+s6T3B; arc=none smtp.client-ip=209.85.214.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="FC+s6T3B" Received: by mail-pl1-f173.google.com with SMTP id d9443c01a7336-24b2337d1bfso57295ad.0 for ; Fri, 05 Sep 2025 14:41:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1757108462; x=1757713262; 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=JJ/emNLCJz3vxOzQ9R3rq9Yl2yjJO1c1zooZAILHbKw=; b=FC+s6T3Be9OhbfE3d46wlRbNypqlcHGfaR3fU5bGf9ZyZZ2fmGWCSbQb8rlZzeCopj pjofAdVG2MdF0FLFJNlh06l1AmQhy0a4E+kRIKUgBoRZssqSbeOHgvo8vu7514bZHzPK iDT+AMRi0oWyCNR/ccVAKWZKlLYIgihTf0MA6nv+onyUu+RUvcXDwHJ727YGTjOItv0X dPVBLYEr/8muy7TKkxfBC7ig1GE4nqlEcJTYe9jyEuqO296rAivFxzq/b+lBSBHrxoIQ GgNavhIfeBMjXK+1dBa645uzHc1zrm5STYCy4wgaq4yAN/kfLWnwDPyvDSipNESsqV2n CGBQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757108462; x=1757713262; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=JJ/emNLCJz3vxOzQ9R3rq9Yl2yjJO1c1zooZAILHbKw=; b=wPvSZOId5CNRqso/BaNOCDkm2sZA6iouSFutYidBNcQQFF1OqOdjg3nXDlg0/Diyy8 3ooWGGTs8iaZBLmFgol7pKgSDzvCShxmQUp6WAyFGDVt4PHVfrqk1vhHlvC9FtJtzuBz 4ypzhuKwD574x+WPmyQN8K77m7Ek/kEqrXhEgmnPj5Y4Lv1Cfk255eq0gRn6uVRCEW4k 79t3ioH3PhCD9OgYIAo70hWFLV/3pHIrcLWkC5xcSj/p72WwGRoyReOakFBlwJ6tQs8M n+rj+mllHxhTkgKVMcpBvxJk1Qfn1kXnF+275a75RutlO/j/X5sVCSMIxI87WIjnYUsw 1J1A== X-Forwarded-Encrypted: i=1; AJvYcCWO2Q1Yh+J6QplvOB21OSjkPPqVYUXlI6uX2uAgRKZS6XU4Ds03nZNEG1khr26KA18CJTI=@vger.kernel.org X-Gm-Message-State: AOJu0Yw8mc5svn9St6VWYKj+ay8Gm0vKRD+YZLmsvxRgR50Ak1JtpCEL 74JRrGrNlO/gsr0ph54NFNlxCS9dcn8xecAtrSDJNks0Kl/xybv9W25god0gpO8chQ== X-Gm-Gg: ASbGncsiPWQ3lv8c2VZ0cAm3QCwXP+tQseP/3QiaGctGQSk1c8wH47zHn6G6+tvJSMF HuER8vTVbiOd5bgui45RszBZJqNNV6ns0uBi/mGKoIzOb8iksU1Yqr8Lenkn7YdQs1q1xjOvLv+ F2/ymsiuAKX0jtR0hTEjzyPPPwO9XXBvesCW/Ehtl+lGOFSINe7XSeAt1TUG0PcgKqEdfAkFGjf Hoawlf8VfrznbCevWyq1QQ0LeMxFRY4i95z5Y1iPO5lwDLediaTfpmXJ6NMN0YfqyJT8VUdN6MJ xdWX6MUC3re1qxxbA3cdFHrJ//P0w/tkdGLLFdLvtweYdR5t83YgJTNAuAFRy00dPkplIoJllj9 LKQxMFsngxhThYkg16ejo3iibxVb93XoD+iO+9wkb1vFdwS+JaNKZxm4mqNT40xaebv4= X-Google-Smtp-Source: AGHT+IEgsoKeEdAOmf7V3AwPOG3rhylbsP/X4Pjd1kcqhKfVj8Dc8zkYrCPZC0GXi2o1KWjaV1iW6Q== X-Received: by 2002:a17:902:f546:b0:24b:9056:86a5 with SMTP id d9443c01a7336-2517446f701mr288115ad.7.1757108461368; Fri, 05 Sep 2025 14:41:01 -0700 (PDT) Received: from google.com (132.192.16.34.bc.googleusercontent.com. [34.16.192.132]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-7722a2aaa70sm22678386b3a.24.2025.09.05.14.41.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 05 Sep 2025 14:41:00 -0700 (PDT) Date: Fri, 5 Sep 2025 21:40:56 +0000 From: Peilin Ye To: Shakeel Butt Cc: Andrew Morton , Tejun Heo , Johannes Weiner , Michal Hocko , Roman Gushchin , Muchun Song , Alexei Starovoitov , Kumar Kartikeya Dwivedi , bpf@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Meta kernel team Subject: Re: [PATCH] memcg: skip cgroup_file_notify if spinning is not allowed Message-ID: References: <20250905201606.66198-1-shakeel.butt@linux.dev> Precedence: bulk X-Mailing-List: bpf@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: On Fri, Sep 05, 2025 at 02:33:16PM -0700, Shakeel Butt wrote: > On Fri, Sep 05, 2025 at 08:48:46PM +0000, Peilin Ye wrote: > > On Fri, Sep 05, 2025 at 01:16:06PM -0700, Shakeel Butt wrote: > > > Generally memcg charging is allowed from all the contexts including NMI > > > where even spinning on spinlock can cause locking issues. However one > > > call chain was missed during the addition of memcg charging from any > > > context support. That is try_charge_memcg() -> memcg_memory_event() -> > > > cgroup_file_notify(). > > > > > > The possible function call tree under cgroup_file_notify() can acquire > > > many different spin locks in spinning mode. Some of them are > > > cgroup_file_kn_lock, kernfs_notify_lock, pool_workqeue's lock. So, let's > > > just skip cgroup_file_notify() from memcg charging if the context does > > > not allow spinning. > > > > > > Signed-off-by: Shakeel Butt > > > > Tested-by: Peilin Ye > > Thanks Peilin. When you post the official patch for __GFP_HIGH in > __bpf_async_init(), please add a comment on why __GFP_HIGH is used > instead of GFP_ATOMIC. Got it! I'll schedule to have that done today. Thanks, Peilin Ye