From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f49.google.com (mail-pj1-f49.google.com [209.85.216.49]) (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 80AF14657CC for ; Wed, 3 Jun 2026 11:30:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.49 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780486213; cv=none; b=ZgxKHE3H9qadfeD0BRQTRRcMR6TMxbOMFHTajrdzB7Diboy5n2tsVx2HuuvQk6smtaPGiDrEgWnQdXU3f8FMHWrZ3A9Zoetk9oIAH+vD/KOd1t+EsFA1q9LpW3UOfXmXORrRx5Z2RGJlQRAkq7MjHIqW8L0Bc+CVCec24RlNdGM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780486213; c=relaxed/simple; bh=xOTX+MabhctCMO0AxLM6gpxNigvHpYgWMa7i9UOhHnY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ZI/TypIHSFaG01tGLRKMPKR/36AZKSXvh47rEe58UGuZkZ8fIttH/BnFsy+7/YacRTCoYr/kvRwI4H1TX/PTDEFnGVZATdYaw9k5U6+mlJBbJ7LHnykws2IhoerUg29p8qUIpHIYSSeeuaxJ18hWYOKEkIWbBgGt8mc2w9Jr9Wc= 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=HflTiosm; arc=none smtp.client-ip=209.85.216.49 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="HflTiosm" Received: by mail-pj1-f49.google.com with SMTP id 98e67ed59e1d1-36bd175fdbaso3004116a91.0 for ; Wed, 03 Jun 2026 04:30:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1780486211; x=1781091011; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:references:cc:to:subject :user-agent:mime-version:date:message-id:from:to:cc:subject:date :message-id:reply-to; bh=QbLgrUUeNFGNskm0gEJ8DV84HGEbh6GoBjogs08lHeE=; b=HflTiosmYDes4tYn6xBTvtNMA9IHO7j7HDcC5GlLcw9p08u59BhVroSdNUHxvM+FMU u1esqBX1BrZq8bEUKgpKVwTIat6I3AdlOwTkyrwlbF5AluWNAGyrXjjDizqIfDWJTyJk 4eYKVBsAQ6losAOMrAnQVCJaico1mTsopPAiDMV76utdbI1H8dq9O74nSI8Fd+DrJg8I NmFeH7ZQsnc67GIP/iztZo8OVpQaEbr/32/4JgSbINU4tPBOrNsO0hEHPKGDJ+dWRlof ZfXWaCJmvNkKuZTmC/MAqjpiF79/TJrD+cDX24mTd1BFlj0odbYgsf7a8rUo/rcP56iF EXKA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1780486211; x=1781091011; h=content-transfer-encoding:in-reply-to:from:references:cc:to:subject :user-agent:mime-version:date:message-id:x-gm-gg:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=QbLgrUUeNFGNskm0gEJ8DV84HGEbh6GoBjogs08lHeE=; b=n5VIMUT+vnDarEFaDgP3NQJCG5B6s1VX5mRQ2Inzgx7IEIrLiqv/yXS0xfkNGUdGcr oZeFzStle+9x/I9uivfxKA4KvQxTdUDc/RRUHW3uUjstjTIWvS0PJmKBHNEoGsJL2syy G3hkW8Y/IZ5l4eGMbCHRjvT10R+qHjBlxESZtw8c28AVc4H0X+NjGrvgZpo9Ku05O25M o6vKFt9J1/duacKSq7rtTROlaH9AJrDaufkiHXplPDq9zJmKrhKbqdpNRyazWQ/EoeFT UxJm6e11cx07QqWbslgt6POcn+TPSk1GzoT8QUv29BTtVsOAr8Fqwbc8lfXKhG7UEn9y /wfg== X-Forwarded-Encrypted: i=1; AFNElJ8uHlyTDVuK/Y3+1Jzufd+7SEDhp1OTaLj/9dtFpCGWml8ApsBTN7MeGPgVbUMr0t3BtafdpN4cknSyNk4=@vger.kernel.org X-Gm-Message-State: AOJu0YwMrvaPSTxq2T3/aZQw7SWvqysjKS8dOzCf2JxWoLjvgam9XfEV OT8TRX/O9kMNdVTXDApl1Xtrk+CRLle7YyONFWacrN0hpdGw/44N2C7g X-Gm-Gg: Acq92OEMuVes7sIN5UxF2FYe/YV8tnaqkEk5EfFk7BTR/j10JDGdjrikC7fZhdaW9qe bxvScWP+eIx0aHEjLSHf2R6DqnQEa+jHsx5x/Z9yUjNbiNLLwxK5M6li8XByQvL3/OkUgj1HaJA vHZ8Lq0Y9C/2MJ8YJfZ5PISIASpR/tfT619NaYg3HClcSx7tJ0iW+9PpIrw5hm/eJV65FDcGcpm CEvM1Cl3lwgeYsHcT/TFPsJppckR6xsLVIavXuz6emaa07WfXs5mr0nPVP/t0LDgCGusLllkQKI zuskmpZdJ6AysnJkXJtdiG76GUw3wfLMFqRtqQmmDetq5bhqIkLr5BZUj1BHiH+gFzgPUdogiDs IVPk0a+hgVhPuPRjGwqIUE1SRkm6z3Ih1eeurMyAkk0wg09Js5ptlFoiMETn3zL16NpS0u5qrNP VoHdn4lJoCKXlY6Ix8fgVvZzjyAxb7fDRDGO1ppSGYIAC3eLGiqCo/Vda9+icgZhHu X-Received: by 2002:a17:90b:2d8d:b0:36b:e8b9:46a4 with SMTP id 98e67ed59e1d1-36e32285cf3mr3042276a91.14.1780486210499; Wed, 03 Jun 2026 04:30:10 -0700 (PDT) Received: from [10.125.192.75] ([210.184.73.204]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-36dd91820f3sm5910449a91.2.2026.06.03.04.29.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 03 Jun 2026 04:30:10 -0700 (PDT) Message-ID: Date: Wed, 3 Jun 2026 19:29:56 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.15.0 Subject: Re: [PATCH v3 3/4] mm/zswap: Add per-memcg stat for proactive writeback To: Nhat Pham Cc: akpm@linux-foundation.org, tj@kernel.org, hannes@cmpxchg.org, shakeel.butt@linux.dev, mhocko@kernel.org, yosry@kernel.org, mkoutny@suse.com, chengming.zhou@linux.dev, muchun.song@linux.dev, roman.gushchin@linux.dev, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, Hao Jia References: <20260526114601.67041-1-jiahao.kernel@gmail.com> <20260526114601.67041-4-jiahao.kernel@gmail.com> From: Hao Jia In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 2026/5/30 04:01, Nhat Pham wrote: > On Tue, May 26, 2026 at 4:46 AM Hao Jia wrote: >> >> From: Hao Jia >> >> Currently, zswap writeback can be triggered by either the pool limit >> being hit or by the proactive writeback mechanism. However, the >> existing 'zswpwb' metric in memory.stat and /proc/vmstat counts all >> written back pages, making it difficult to distinguish between pages >> written back due to the pool limit and those written back proactively. >> >> Add a new statistic 'zswpwb_proactive' to memory.stat and /proc/vmstat. >> This counter tracks the number of pages written back due to proactive >> writeback. This allows users to better monitor and tune the proactive >> writeback mechanism. >> >> Signed-off-by: Hao Jia >> --- >> Documentation/admin-guide/cgroup-v2.rst | 4 +++ >> include/linux/vm_event_item.h | 1 + >> mm/memcontrol.c | 1 + >> mm/vmstat.c | 1 + >> mm/zswap.c | 41 ++++++++++++++++++------- >> 5 files changed, 37 insertions(+), 11 deletions(-) >> >> diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst >> index 6564abf0dec5..7d65aef83f7b 100644 >> --- a/Documentation/admin-guide/cgroup-v2.rst >> +++ b/Documentation/admin-guide/cgroup-v2.rst >> @@ -1748,6 +1748,10 @@ The following nested keys are defined. >> zswpwb >> Number of pages written from zswap to swap. >> >> + zswpwb_proactive >> + Number of pages written from zswap to swap by proactive >> + writeback. This is a subset of zswpwb. >> + > > nit: I think this is specifically the zswap_writeback_only mode right? > > Technically, normal proactive reclaim (memory.reclaim) can also hit zswap :) > > Maybe some clarification here? Thanks for the review. I will clarify this further in the next version. Thanks, Hao