From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793969813; b=qL4m+DB8o+V5OIfxlOaXARlkB5J3MiCeSU2BkcSrN7Lr9faOA860OefGFX4eOuBtliVW IL7mBZqst9w6dxdOwoYBlGZOWnX3/ytvJe5RLVfSQNjFe7vb6/SQLS7v8YXN2Jb7Hgtry wqOjmQ4MkONCM6gNsS03OuJXDc1kSihxAvSq8TXoUzUiLgkdvTdi99l2mBOlvEZTOY6pO GyTAimD4zBikZM3egS4rAhJ8GkT/ZADysGvNAkzuYAMgcnOsaTUvpyrjr7zuq3oA4N2zE DvLIeBojT8uz8+OIvPKLao/00IOuLgqrq/UgooamJnXPUt1fJfgetB9GctDL7WNPRaw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793969813; h=Received:DKIM-Signature:Content-Type:MIME-Version:Message-Id: In-Reply-To:References:Subject:From:To:Cc:Date; bh=9VpU3s4yf4A/VkVgs+2HUp63ZM4Ff63clTXzeYeN/bk=; b=5dkwEYHyRkpORtc+TqvIP59+KKlr4swH7gar/RmJxbszmKCqGirZ1dzwlZLuug0vcsMW t1kq82citAJ42VA8ZwMzdJGhQ5vbPnaIqMN6Ejg9tFU93t4vgPDIjbFH03UliQf2mWUW7 2YUzSUZ+tOy1sIwK1ZpDtrXMx9prXxmu09Cp6UMqFINyKdEi2c17f+jOmYwrUq+7ggbcS CSc6TvCSIK/gADNVfYGgSngSKZWhgyaw8smQ2aPVwShQoxZ8YB+J4PmELNP+mxkEBMMk7 sEGExFWjU4RBvcYpC06/yoz1Ws8TnSp+zvszx6qKIKSiPZEUFAgyGBpmUgTZzWDDtEw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=BH9StoNJ; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BD4F1606A329; Fri, 6 Nov 2026 12:56:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=BH9StoNJ Received: by smtp.kernel.org (Postfix) with ESMTPSA id ED4BD1F0089F; Fri, 6 Nov 2026 12:56:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793969812; bh=9VpU3s4yf4A/VkVgs+2HUp63ZM4Ff63clTXzeYeN/bk=; h=In-Reply-To:References:Subject:From:To:Cc:Date; b=BH9StoNJ1xXxrVEEBPM8Ch07tAFIxs8WM0IsZ/48kp7d0BvVgupAJALLQM2mUSbHl nN44VMHOaeqcWlGhLfhRv3FuWioIu/6Rpj32Z8kCvXEOuKI8UsMeeKZkJRZHnDg2BY hmuWPsiXpPMQXwasalzHNfKZb3g5ACNiiYEGCMox4Xu9qcKlk04KaR6YKmL9K4VlmG +KERQwfwcnMm0uvMvngoAmgAstf4cSfptmWM66Y6uP9vFWbJIKDitFxIBO5f1JlBXm q3K78m0FDQ15G233GHkGZVakKQ8VkN89I2iqkkUrUns9+yVonk5Kr3/y3f0j1yD37o NWlt8rAwmRFnA== Content-Type: multipart/mixed; boundary="===============7202935202910912622==" X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Message-Id: In-Reply-To: <20261106122356.3224638-3-cui.tao@linux.dev> References: <20261106122356.3224638-3-cui.tao@linux.dev> Subject: Re: [RFC PATCH v13 2/4] blk-iocost: add iocost_ioc_tick tracepoint for per-period device summary From: bot+bpf-ci@kernel.org To: cui.tao@linux.dev,tj@kernel.org,josef@toxicopanda.com,axboe@kernel.dk,alexei.starovoitov@gmail.com Cc: cgroups@vger.kernel.org,linux-block@vger.kernel.org,linux-kernel@vger.kernel.org,bpf@vger.kernel.org,andrii@kernel.org,eddyz87@gmail.com,ast@kernel.org,daniel@iogearbox.net,linux-kselftest@vger.kernel.org,cui.tao@linux.dev,cuitao@kylinos.cn,ameryhung@gmail.com,ast@kernel.org,andrii@kernel.org,daniel@iogearbox.net,martin.lau@kernel.org,eddyz87@gmail.com,yonghong.song@linux.dev,mason@kernel.org,ihor.solodrai@linux.dev Date: Fri, 6 Nov 2026 12:56:51 +0000 (UTC) --===============7202935202910912622== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit > blk-iocost: add iocost_ioc_tick tracepoint for per-period device summary TL;DR: Commit message only: it restates the code comment instead of giving the motivation (monitoring without drgn) for the new iocost_ioc_tick tracepoint. Not a bug. > blk-iocost: add iocost_ioc_tick tracepoint for per-period device summary > > Add iocost_ioc_tick, emitted once per period from ioc_timer_fn() with > the overall controller state: period_us, vrate, busy_level, active iocg > count and usage percentage. busy_level, cur_period, nr_active and > usage_us_sum are complete at the emission point. usage is wall time > over wall time, summed over iocgs, and is not capped at 100. vrate and > period_us reflect the current controller state, which an io.cost.qos > write may have changed mid-period. > > The event fires every period the controller is running, including > steady states, plus one final tick before the controller goes idle, so > the transition to dormancy is directly visible. The active iocg count > is only gathered when the tracepoint is enabled. > > Suggested-by: Tejun Heo > Signed-off-by: Tao Cui this isn't a bug, but the middle of the first paragraph ("busy_level, cur_period, nr_active and usage_us_sum are complete at the emission point ... which an io.cost.qos write may have changed mid-period") restates the block comment added above the tracepoint call in ioc_timer_fn() almost word for word. The reason for adding the event only appears in the comment in include/trace/events/iocost.h ("so basic monitoring doesn't require drgn"). Could the changelog say why a per-period summary event is needed, for example the monitoring-without-drgn motivation, rather than repeating the code comment? --- AI reviewed your patch. Please fix the bug or email reply why it's not a bug. See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md CI run summary: https://github.com/kernel-patches/bpf/actions/runs/42219005018 --===============7202935202910912622==--