From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 F3A1A25A33F; Tue, 7 Apr 2026 18:27:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775586463; cv=none; b=XkMlzoQEyw6hkGGWYKd5T6W/c7vg0o0QHsELFPC38b6SNoGvBx+2Runul56hX25Vy7WZauvYhOTpfoIe/UzqwR/dNpL0oeVXGPoYIQygCNAyRZrPAEKTjC1XXajS16zXNTKDoCL1zAZMzsFTVYq28iHxuQg4904tGox0pB/OGIo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775586463; c=relaxed/simple; bh=GzIaObYHKSieBS5jLgatarytMYl0UMmRJKIRCoGKfXQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HOsucq3ZQfn0A0cIfLGqI6aQ4wimic7tBMBeTqE3+5UoSd0eYuy8mvjD0EaZYOKW+X5U0g/X6hHHp90NfuBoj/XZFbQI3ZJPqiSR9L38KjKDLIjEJ+xmkwj02dfR8aUzd36zHMrelsz3BPNXTVWKxll1PqYDLYKb2uaRjZAw10Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=X95BrSni; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="X95BrSni" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 78092C116C6; Tue, 7 Apr 2026 18:27:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775586462; bh=GzIaObYHKSieBS5jLgatarytMYl0UMmRJKIRCoGKfXQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=X95BrSnixts2JtFkkb0kUqeQUzwArmSC4CX1ClUOenAM94vmbVHONlpSu7H5IBDSt Y9Xk6sMKQj9BPVvM0cYolM6ucD5gNoqPSDDVtpwPRBpaYqWXjHjLB7fcpyURvvebD/ n3z433EM1XGRNn7FT9ox2aum5EWsd3c4ZllI+K4pA/T3BIcXopogqGV6nNqQqVOk08 lRl7LlUqVbyrqATWZensWkaZAdy6WEMYzW8mqpv8I9dFf0IhwLLVwO1gWpB+7VObgJ BmpSgpL3aMAS+evdY9d8Pt9nwchevrHYslJ3ZoUHd+AAH8uoYQ+5NlmXjDFqKSA5L9 bzDuB/2jmeg+w== Date: Tue, 7 Apr 2026 08:27:41 -1000 From: Tejun Heo To: Willy Barro Raffel Cc: Johannes Weiner , Michal =?iso-8859-1?Q?Koutn=FD?= , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Justinien Bouron , Gunnar Kudrjavets Subject: Re: [PATCH] cgroup: add cpu.stat.percpu for per-CPU cgroup stats Message-ID: References: <20260407010642.3249-2-willybar@amazon.com> Precedence: bulk X-Mailing-List: linux-kernel@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: <20260407010642.3249-2-willybar@amazon.com> On Mon, Apr 06, 2026 at 06:06:43PM -0700, Willy Barro Raffel wrote: > Expose per-CPU subtree_bstat via a new cgroupfs file cpu.stat.percpu. > Each line shows one CPU cumulative stats in io.stat-style key=value > format: > > cpu0 usage_usec=123 user_usec=45 system_usec=78 nice_usec=0 > cpu1 usage_usec=456 user_usec=123 system_usec=333 nice_usec=0 > > This completes the interface left as a TODO in commit 7716f383a583 > ("Merge tag 'cgroup-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup") > which added per-CPU subtree_bstat but only exposed it via BPF/drgn. Given how quickly cpu count is increasing with 1k CPUs on common prod machines not too far off, I'm not sure naively formatting output for every possible CPU is desirable. Thanks. -- tejun