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 3813922AE45 for ; Thu, 18 Dec 2025 08:54:39 +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=1766048080; cv=none; b=bL9wH3vstBv14Iiw4/4ut75LMlZ2t84uH1N3dojnUMnW9G5rz7bLQq/WFazaA16MjCB8gwdVQiOGPzplhDcgEPEAZxVpRSLivIqNVrn8VGTwLaI/zAMNpncqyxLW1+qlYiZzKlZ04U2IMPvQoVqHKtTRPdjEcbYegwXdq3vJySI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766048080; c=relaxed/simple; bh=+qNn/OJjWWHP/A0urQ0xX32Xkqv6pMC2TNNdJPZPvyY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=oDLGqP6t/8stOqwOnk+zUecj3A2t079/HWxzTxJJeuqcBvFZU0/rkQgQwku5huk6vyhh2NGmWIiRXTmLMt/FY/rmeduq6WAvg5nB5QVoUF9nnCi6RmTm8T8UBLzasrox4L4+T9Q44JuqarwllWeTtyGHGomlIaQDYcgAHsitBy4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XrTsMpU7; 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="XrTsMpU7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2A109C4CEFB; Thu, 18 Dec 2025 08:54:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1766048079; bh=+qNn/OJjWWHP/A0urQ0xX32Xkqv6pMC2TNNdJPZPvyY=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=XrTsMpU7hllhZ04KswkkiRAm06vv33hh3vVu7hHjiwrS6MOBlg5cz44P6Pt7JF1Rv ENfgZDfCn2LVf8z4m/hXaPOPAxxpH9QeSPYYBamwWnfUS6TItgeZ3Qey94JFbHWD0w 3FQFSegoDFA1lk8DCx2p8yUzI0WPcrCJCtg4GDWYN3nI010FN1zcqn3fQsIHrrOajB Of5neRDjWPRC4CJZVAg6a3e8CvluVYtqhIZH+y9X+FeRS1u18WkfmAj4Jxk3TNB3do c0uUqV5D0aLM5EdD4kc7se6IW6vgbjYzC3YgGmv0cxWACYKMCPXrg8dbAoiEVTxR/X oITCvGrbiH6ag== Message-ID: Date: Thu, 18 Dec 2025 09:54:36 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/memory_hotplug: Cache auto_movable stats to optimize online check To: Swaraj Gaikwad Cc: akpm@linux-foundation.org, david.hunter.linux@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, osalvador@suse.de, skhan@linuxfoundation.org References: <20251207231056.71294-1-swarajgaikwad1925@gmail.com> <20251218064159.7230-1-swarajgaikwad1925@gmail.com> From: "David Hildenbrand (Red Hat)" Content-Language: en-US In-Reply-To: <20251218064159.7230-1-swarajgaikwad1925@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 12/18/25 07:41, Swaraj Gaikwad wrote: > Hi David, Hi! > > I’m just checking in on this patch to see if you’ve had a chance to review > the benchmark results I shared last week. Not really, still traveling and this is veeeery low priority :) > To recap, the caching reduced the > execution time for the NUMA_NO_NODE case from ~2402 ns to ~453 ns in my test > environment. Yeah, but these micro-benchmarks don't really matter ... at all. What would be interesting is what happens when you hotplug a lot of memory to a system with a lot of nodes. I suspect it won't really be a problem. > > Please let me know if the performance gain justifies the change in your view,or > if you would prefer I send a v2 that simply updates the TODO comment as you suggested. I'd prefer if things that are not a real problem would not consume my bandwidth while traveling ;) Anyhow, there was a kernel bot complaint that you are using "struct auto_movable_stats" before the compiler knows about it (and its size). When you resend, make sure to better describe the "why" we are doing it. It cleans up the code a little, so that could be used as an argument. -- Cheers David