From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f169.google.com (mail-pf1-f169.google.com [209.85.210.169]) (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 F04661F3D56 for ; Thu, 9 Jul 2026 15:39:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.169 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783611576; cv=none; b=V7iLiKOMi+UjqhrWict7hTuZmqjN+eEuXr9oRQkWlwhe0CNvDmOQdKTGwTkdYqygi3+Nszg7ff1ll2DrPBl+ovIdolgWnEWKj14+7dJSONIMGhRvZ55cWzzMXmtHhouO8KHDJhl9+hW99NqQjzZwI4Kh46HncNmSTe7co1CpUDM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783611576; c=relaxed/simple; bh=R07iPGczI9CMuDV0hOy0iNA4x3E3zIrOkLWW9OgU5bY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=iFhbEast0Lrs/ZBcn6OHZkP26XvXccmfZ3iRc6tD4HG9+3izQrePTdQ7bklCEMNpGgyHWthlQXoQdf494fa+XPn3NaL3fE+rWpaWNSFn7uxMlnC5KQo10mwQZUybjOeAJyTM8XPQ3t41HvhGAkLAc2wymWUBqpWO6NhuEd+05KI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=MW/3wwQs; arc=none smtp.client-ip=209.85.210.169 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="MW/3wwQs" Received: by mail-pf1-f169.google.com with SMTP id d2e1a72fcca58-84537d04408so101554b3a.0 for ; Thu, 09 Jul 2026 08:39:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1783611574; x=1784216374; darn=vger.kernel.org; h=content-transfer-encoding:content-type:mime-version:references :in-reply-to:message-id:date:subject:cc:to:from:from:to:cc:subject :date:message-id:reply-to:content-type; bh=lXXGap0Q/LiZLJdfHOXl3AEYRU8Fj6byPx+ImpQAltY=; b=MW/3wwQsArRbjmfHx+GQxCpb6sE0rnlhThiXJj//cFt2f/8ukD5D8wdhC426OqIWU1 coDhkkEQcyW3icnPBFtdEGu6nv64V1ASjWaxf8kEImoFA8WhIvzYWXCG5fIK5Fazeml6 glcLUAuT2vjIh/U2dSYGGIppYT8sBIHT1nK6VLDIOCo+ILE0J5cJ1BA6adfL9Ka9/JHL J8PpRSMhN7bDh20AciNAFPBOzLspj+nFr13DYWSBM24UqISksYiE2jMpsYQ0NLXlzQwL V2AQ7BY9wmuZWBxGQvUlBfZgzrojL3pd/OTO9rYULPM8oecXJO0oq4YtuxlQi6UWyrhT mNrQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783611574; x=1784216374; h=content-transfer-encoding:content-type:mime-version:references :in-reply-to:message-id:date:subject:cc:to:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=lXXGap0Q/LiZLJdfHOXl3AEYRU8Fj6byPx+ImpQAltY=; b=X+TJmyuPnJwkuNlwR6/aKGQFVgqq5g6WOHLBbCptJyuew1wEZR59HkZM61R262T5jy 65kxj/JTshuTaOQJmJJEmYYfbEJaoN5RXKIatlkT6eO23zatyYXZDjEX9N1uDuiCDA/p vMwS176wQwOv3rrM1YdlZ9w2RyC2aU9nlrW7xxzhF0s4jODsyH1pYLdgssXAdkS7+vJ5 02FsRgofSTU2npjgu8nO+P7GamYdL2Y73zkNQui69FFV0Y4WbaMRqqQIFsw5jCKqw+k3 54zmVFhk6ubLRh9jwloxmtKCXUJrwKLpnodQj/YW8gWWnYnffqzfTFd2EN0oWfAnrAyM Lghg== X-Forwarded-Encrypted: i=1; AHgh+RppRbLlZllRwib1RsmdEh7wivup5i6lzSGw8WO7Xw8Jr3NrFl7O7/Y9sSsHXb/JH9T5EPb/lo7N@vger.kernel.org X-Gm-Message-State: AOJu0YwacsyFfjwViliksjCFNpo4vjxZssQc755xmBlY+aF3bYTmHJXu UiIlTJ1QEMjekMAH6Ig8GeaCXbmES82Md/vgg8hB5ZXBCP5Xqgb+Hx08 X-Gm-Gg: AfdE7cl5UtXiSR0TSZVH5Dj8GNdC2dtUErKEFyYNmEjCBCgbS5MFzDzR1/GdXLd4yy1 fB9BYzzat2cXu4BNeKFzvTDTQslwSqrEVbETWxhdxrM2YIcfFL/ps5sXutoCY+6w6WhzbzLI5fK J/PH6fxxM5HNPg7JzflTt+D+mwCUHcn2NN8ZS/EATkB60OXUfPsNCRKXl+VTtYw4vK1xmtNRqA3 lgI24eyf4iOeWi2GGjfidwKTgJh+AFjAT0520iokAe6EoSavMdwsZSTbRrbkZ87yS5ojwq6cXju LIJ0meZWJNmNUPJGzIl9QRxY0EBbdfxOlFFPya8olpERa+cj/UI5RZoEVYrv0JyJ1WZFAJiROYo Yyy5jzCfs6TKmi9Te8O2uf56WKAmxnhkdTjjell+xyiHO2cBKnMA/Q2SMNFFboQH31GVeRe/Lnm tX3a9TkVP+euEOFdyDrxBpuRpyTT3bJA3KbgqHrETTHOSuPv5BdLfnk9Q= X-Received: by 2002:a05:6a00:a93:b0:847:8971:87d8 with SMTP id d2e1a72fcca58-848560021c5mr3191674b3a.6.1783611574014; Thu, 09 Jul 2026 08:39:34 -0700 (PDT) Received: from debian.lan ([240e:391:ea3:6910::1]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-84856d5d619sm1491303b3a.39.2026.07.09.08.39.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Jul 2026 08:39:33 -0700 (PDT) From: Xueyuan Chen To: hannes@cmpxchg.org Cc: xueyuan.chen21@gmail.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, baohua@kernel.org, zhaonanzhe@xiaomi.com, mhocko@kernel.org, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev, chrisl@kernel.org, kasong@tencent.com, shikemeng@huaweicloud.com, nphamcs@gmail.com, bhe@redhat.com, youngjun.park@lge.com, david@kernel.org, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, qi.zheng@linux.dev, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com Subject: Re: [RFC PATCH v2 2/3] mm: distinguish large folio swap allocation failures Date: Thu, 9 Jul 2026 23:39:24 +0800 Message-ID: <20260709153924.772408-1-xueyuan.chen21@gmail.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: References: Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On Thu, Jul 09, 2026 at 11:04:23AM -0400, Johannes Weiner wrote: Hi Johannes, >On Thu, Jul 09, 2026 at 11:01:12AM -0400, Johannes Weiner wrote: >> On Thu, Jul 09, 2026 at 10:51:23PM +0800, Xueyuan Chen wrote: >> > @@ -5550,10 +5558,7 @@ long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg) >> > >> > if (mem_cgroup_disabled() || do_memsw_account()) >> > return nr_swap_pages; >> > - for (; !mem_cgroup_is_root(memcg); memcg = parent_mem_cgroup(memcg)) >> > - nr_swap_pages = min_t(long, nr_swap_pages, >> > - READ_ONCE(memcg->swap.max) - >> > - page_counter_read(&memcg->swap)); >> > + nr_swap_pages = min(nr_swap_pages, page_counter_margin(&memcg->swap)); >> >> This hunk is unrelated to this patch. Don't mix refactor work with new >> functionality. Make the previous patch a pure refactor job (where you >> add page_counter_margin() and use it here ^), like I had proposed. You're right, that refactor doesn't belong in patch 2. >I also liked my version of mem_cgroup_get_nr_swap_pages() a bit >better. Please just use my patch, keep the From: and you can add > >Signed-off-by: Johannes Weiner > I'll use your version in v3, keep your From: and Signed-off-by, and make patch 1 a pure refactor patch that adds page_counter_margin() and converts mem_cgroup_get_nr_swap_pages() to use it. Patch 2 will only keep the functional folio_alloc_swap()/memcg charge changes. Thanks, Xueyuan