From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 94DD238B15E; Sun, 2 Aug 2026 21:32:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785706371; cv=none; b=mUbVPGgAvq15jCj6dcgUatXv8ccfkrG8Lba/sadgWbBKYyrmvfI19Q/NfTyK0ghljq/p3+Xsfv00AYMM56XAIJnvCHDX5IFXmSwIt22j8trRf8OmFl13r82rJHWYdMOexhFHegegKeD4nWKl5qZg4Xcxx6PpED7KPN0oIfOxGNk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785706371; c=relaxed/simple; bh=KOljYON3jTRUwQm8eUqMu5CjveCeO2Eiom0kk+/OeRg=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References; b=HfueIvj3iN7vvl2GcJGAOyw5dcHTPsZBOq2ztl/3jNRhnx+iPG3Sh9BAC5HfWBqqR6lz3S35Nu8ArVtpXVWKSXdbx3fV6JmXm5yA1t3WBBKYaZ9L01VgVFJMnste8h35X62HFpIKQBK4XN+TQdPxN+xjxCRoaNYgsDdWHTyytXU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZPmjozn/; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZPmjozn/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 11F181F000E9; Sun, 2 Aug 2026 21:32:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785706370; bh=cDzhkG1w+YnSNaNsYPGfzaniZU7En9exAEkV+7q0Dbc=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=ZPmjozn/UqJ6ojT7xQXerEt+1sQb5lqXKF1qpwS9oCcKg9L7LOxssF7ng18B9nENp c3HiFce/7HjdmeFruI11cWzXwbmTuoEk7hXji7Njw94Dn43DTeSJGXuTGnf1QnPCcR DOI7PXDaEVtLEDWZkc1WuOVab1jDjlNiLtPKlvH5hh1MphQvEv2+PDTPgBgl7dQAlK cTk6yRmTsTSEwU5psGSY/Y8Mvdv9/2OZxbbOlGf1cZw/ULOslPsZOPRM23aXSFKFhd qwkLk3Sww4gjh9D/ikwQt/UfSnKjJQfU0XxhD47PueMXQ6mySwpVzSP80EvelnOpZ+ 9TK1cP27tGAEQ== Date: Sun, 02 Aug 2026 11:32:49 -1000 Message-ID: <14bd63f0e59ce815ec1a1d066f578aa0@kernel.org> From: Tejun Heo To: Tao Cui Cc: hannes@cmpxchg.org, mkoutny@suse.com, corbet@lwn.net, skhan@linuxfoundation.org, josef@toxicpanda.com, axboe@kernel.dk, cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, cuitao@kylinos.cn Subject: Re: [PATCH v4] Docs/admin-guide/cgroup-v2: document io.latency rotational vs non-rotational behavior In-Reply-To: <20260728095707.2398498-1-cui.tao@linux.dev> References: <20260728095707.2398498-1-cui.tao@linux.dev> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: On Tue, Jul 28, 2026 at 05:57:07PM +0800, Tao Cui wrote: > io.latency is documented only in terms of average latency and the avg_lat > stat, which matches rotational devices. On non-rotational devices a group > misses its target once enough of the IOs in the window individually exceed > it, and io.stat reports missed/total rather than avg_lat/win. > > Describe both cases: how a miss is detected, note that the avg_lat tuning > guidance is rotational-only, and update the io.stat field list (mark > avg_lat/win as rotational-only, document missed/total). > > Acked-by: Michal Koutný > Signed-off-by: Tao Cui Applied to cgroup/for-7.2-fixes. Thanks. -- tejun