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 2D73B35960; Wed, 15 Jan 2025 01:10:46 +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=1736903447; cv=none; b=O5KX2b3clv1x3AeUELuyksRwJf2fk2ntPXWpjpGOXI/izxtyAFAIydLn4uuBWMABAkTZBkyfsImt23XAk33vraf+Otpxj9ZlT09U89KGGLKGM3sUHE7527HaGbm/ZgVV0NA9TeDUfXVdplcrfXqotWEAk5HaiKido36KvunVNTs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736903447; c=relaxed/simple; bh=CVZEHx6Eh830JyI4aKceXPSCIH8O/uVKjeo6hr322K0=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=MCtAPnWcmPEMkwVcckB3eGsooMhd2xt/QeM9sDXDurWLzsZwlFfraPuACtBh9DAcyH904bKEH8z3PxauT5uO6jbzepfvLjZEP0KTBjT57GVIlXSA8vk8gA0ZU2ey6K5fphcq+0HMeVFiTi4sFEEUIWR3l6E6mLn9qwgCDbZB9Y4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=eWEkpt4+; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="eWEkpt4+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6FC50C4CEDD; Wed, 15 Jan 2025 01:10:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1736903446; bh=CVZEHx6Eh830JyI4aKceXPSCIH8O/uVKjeo6hr322K0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=eWEkpt4+9LYfkwGuv6PXIk3wA7xv/c06xCt6oTLN4TNojw1EUKQ/IqoJCmdL0h531 MZkEtJUcydBHl7qmoNHiDEv3TywWqm4MU9gIXG/rdE9jNpnzZhOZjKbZaCsvzgEzFx X1r+iSoPq0OMilQ3Nmdw+5XAbauGxKMAZP4SbrO0= Date: Tue, 14 Jan 2025 17:10:45 -0800 From: Andrew Morton To: Suren Baghdasaryan Cc: kent.overstreet@linux.dev, yuzhao@google.com, 00107082@163.com, quic_zhenhuah@quicinc.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH 2/2] alloc_tag: skip pgalloc_tag_swap if profiling is disabled Message-Id: <20250114171045.e5fadb8db51902ee0181fa0b@linux-foundation.org> In-Reply-To: References: <20241226211639.1357704-1-surenb@google.com> <20241226211639.1357704-2-surenb@google.com> <20241226150127.73d1b2a08cf31dac1a900c1e@linux-foundation.org> <20241226162315.cbf088cb28fe897bfe1b075b@linux-foundation.org> <20241226235900.5a4e3ab79840e08482380976@linux-foundation.org> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 14 Jan 2025 08:38:37 -0800 Suren Baghdasaryan wrote: > > > Well, a 50% reduction in a 0.0000000001% overhead ain't much. > > > > I wish the overhead was that low :) > > > > I ran more comprehensive testing on Pixel 6 on Big, Medium and Little cores: > > > > Overhead before fixes Overhead after fixes > > slab alloc page alloc slab alloc page alloc > > Big 6.21% 5.32% 3.31% 4.93% > > Medium 4.51% 5.05% 3.79% 4.39% > > Little 7.62% 1.82% 6.68% 1.02% > > Hi Andrew, > I just noticed that you added the above results to the description of > this patch in mm-unstable: 366507569511 ("alloc_tag: skip > pgalloc_tag_swap if profiling is disabled") but this improvement is > mostly caused the the other patch in this series: 80aded2b9492 > ("alloc_tag: avoid current->alloc_tag manipulations when profiling is > disabled"). If this is not too much trouble, could you please move it > into the description of the latter patch? No probs, done, thanks.