From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1911DCAC59A for ; Fri, 19 Sep 2025 15:07:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 78516940009; Fri, 19 Sep 2025 11:07:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 75C3B8E0019; Fri, 19 Sep 2025 11:07:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 671FF940009; Fri, 19 Sep 2025 11:07:08 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 520758E0019 for ; Fri, 19 Sep 2025 11:07:08 -0400 (EDT) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 1AF5758891 for ; Fri, 19 Sep 2025 15:07:08 +0000 (UTC) X-FDA: 83906327736.21.AEC181F Received: from mail-lf1-f41.google.com (mail-lf1-f41.google.com [209.85.167.41]) by imf12.hostedemail.com (Postfix) with ESMTP id F221040016 for ; Fri, 19 Sep 2025 15:07:05 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=DS2233iK; spf=pass (imf12.hostedemail.com: domain of urezki@gmail.com designates 209.85.167.41 as permitted sender) smtp.mailfrom=urezki@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1758294426; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=0X7gv2ca1L0/lLvJb6ek6nlX9wHB+NyrwieWqFd2Ims=; b=wbluLZoqjo4F+717I9TZPqxzXz5/QcDjzD8FKk6hiKB0/9ypQOAdlVSFv+NaUUDUzGqtjf DRE8TTPJvIiAd4PWbrZhaTKomV70f+4mHDgjeXt+iX+YYE8eWImBZsofnZtjjCMSZq/VHW ppk9ctBW1B5k8/m1DXMvimqgx/Nz2f0= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=DS2233iK; spf=pass (imf12.hostedemail.com: domain of urezki@gmail.com designates 209.85.167.41 as permitted sender) smtp.mailfrom=urezki@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1758294426; a=rsa-sha256; cv=none; b=VwLiTzGqbaBVGqCupwoM59cWUCbsLHuu9CW3AtuKI/8Koo/kBfAtrUT2hnnCa3xAegG0+k q82zhiW+k3g3vIuYjU/epUpiwyCUl4sj52yPDxU7eNZceyZrKuJvxxzMb9HQEw5dCp3u99 KlLrabOC+UHazfk93dNTAZe0Wav/C/c= Received: by mail-lf1-f41.google.com with SMTP id 2adb3069b0e04-577dd4c1e84so2814295e87.0 for ; Fri, 19 Sep 2025 08:07:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1758294424; x=1758899224; darn=kvack.org; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:to:date:from:from:to:cc :subject:date:message-id:reply-to; bh=0X7gv2ca1L0/lLvJb6ek6nlX9wHB+NyrwieWqFd2Ims=; b=DS2233iKhMFI2d8ccL2YNPO8DSVprRomQRVo5oDV4GE/oU5/qy+ZxwjHHkabYyTIQt Cs+/rSZxKWqZDh2Zv8u0UFieVFYPGVKtx/41HAKwpTJxfHDQTn5tlwRufPf7l6fpEo4r IktO49+rCyPWpKEz0IIepyCVrY86Qbyy1rprjjdIzfzw08aOTOU7u1YbvDb+vF8IRoou Y0DU9yLAVkbwvCr1N5cbDDiZKVQEZVa7p+u2d1HZGb7+rHYK4Tb+90K9QkR7Q5WP19Ay C1iwr1gJL0HhfFE3G+AEou67oZVoSYjEJQI77l+ltZbUWFEPQHheMKfmKiSmkaXJBbry tNvw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1758294424; x=1758899224; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:to:date:from :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=0X7gv2ca1L0/lLvJb6ek6nlX9wHB+NyrwieWqFd2Ims=; b=vvZw8oOJkFaXyHNWw8GVhxfI8N87t0PDn/5npW4HCqbhYtDLsUuEeMkbY8VzGwvbFk OOjqtESudFtZ+TPLnp7XaIP/wYyjT+YBL5yf4rOJLfjqbBisKHYMrMLT/EX7KJ3TghXN QTbF0LZtsPHUelkHvMslP2gMdJO6x+n0XzucBDaRBJq4CWqfLao8kzjXXAgodvQFNsFs IarhTv4/Ag28YNxGQ7vjp4Y2vE3Y4ll4R5t2pPstaPyyo/8Aowqq8d+8wXXc/0Zct099 LGUh8kFcj6mcMgbc2/rSKvJhIA4TfLS+YpZ3XlVR6h6OW/3CR2SvHisNjs3jjWGpuYPT C9WA== X-Forwarded-Encrypted: i=1; AJvYcCU/TUVT56bTpUjtpt8MhNJi/75ZuRJ00Md9OX7tw5iXxh8B7mOrFAurmDbNxeQXS3LFEwlEg+zSHw==@kvack.org X-Gm-Message-State: AOJu0Yz3TIP0o0O+LDOX40Uk5MTjZFJwLmrmBACsXdPj27E4JVlUohtO WkowTkNrwfJSeVLUa2rKumeKXJju8l4vEaSo1EThzn/y9LrAYLB4FTQw X-Gm-Gg: ASbGncsrMHvK+TXhsUBGQXsLT9ph6AGk4wKxLe/3RAO32li8vgCmyZTH5s+i5eY5vD6 TmBYILOeotUrJwNJUmxPCY7boZyXxT0B2s0esFvgo+jSzyr89RWbOyO+c5kJBjjfjc9gh2barz4 a/enFP7CxXX//qqn21pCBOWbtuFO0NU65YX2oluEUhIF8IMTECZX5Rrylq9IONwQYwKkftUIZMg UorcZqwf0uJXOwI6NyfwjYIddHpzTFUFhUcFLDr+zpitaPpZ7bBDCXtIMMspxxaanaMwSgxFzKa kCrUznky3tPvWEGVOnMS/acsqOKKMz2SW0i2vPdIEgR75X84E3DPEgbpB+lu4AFn6d/7DAyrr6N 0 X-Google-Smtp-Source: AGHT+IHlcfeC9Aa/jvbPtaam41unsEAYkZd0ZLBNWZtY3ZSGc+Og1wqJBQuKyUq6sNnJxk0X88wdvw== X-Received: by 2002:a05:6512:1598:b0:55f:4926:df1c with SMTP id 2adb3069b0e04-579e461b887mr1360111e87.46.1758294423504; Fri, 19 Sep 2025 08:07:03 -0700 (PDT) Received: from milan ([2001:9b1:d5a0:a500::24b]) by smtp.gmail.com with ESMTPSA id 2adb3069b0e04-579a1bacef8sm878143e87.103.2025.09.19.08.07.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Sep 2025 08:07:02 -0700 (PDT) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Fri, 19 Sep 2025 17:07:01 +0200 To: "Liam R. Howlett" , Uladzislau Rezki , Suren Baghdasaryan , Vlastimil Babka , paulmck@kernel.org, Jan Engelhardt , Sudarsan Mahendran , cl@gentwo.org, harry.yoo@oracle.com, howlett@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, maple-tree@lists.infradead.org, rcu@vger.kernel.org, rientjes@google.com, roman.gushchin@linux.dev Subject: Re: Benchmarking [PATCH v5 00/14] SLUB percpu sheaves Message-ID: References: <20250913000935.1021068-1-sudarsanm@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: F221040016 X-Stat-Signature: s9yzyn6pcpwti4fp3kzffp67eixzp131 X-HE-Tag: 1758294425-263237 X-HE-Meta: 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 4nOS6dxd 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Sep 18, 2025 at 11:29:14AM -0400, Liam R. Howlett wrote: > * Uladzislau Rezki [250918 07:50]: > > On Wed, Sep 17, 2025 at 04:59:41PM -0700, Suren Baghdasaryan wrote: > > > On Wed, Sep 17, 2025 at 9:14 AM Suren Baghdasaryan wrote: > > > > > > > > On Tue, Sep 16, 2025 at 10:19 PM Uladzislau Rezki wrote: > > > > > > > > > > On Tue, Sep 16, 2025 at 10:09:18AM -0700, Suren Baghdasaryan wrote: > > > > > > On Mon, Sep 15, 2025 at 8:22 AM Vlastimil Babka wrote: > > > > > > > > > > > > > > On 9/15/25 14:13, Paul E. McKenney wrote: > > > > > > > > On Mon, Sep 15, 2025 at 09:51:25AM +0200, Jan Engelhardt wrote: > > > > > > > >> > > > > > > > >> On Saturday 2025-09-13 02:09, Sudarsan Mahendran wrote: > > > > > > > >> > > > > > > > > >> >Summary of the results: > > > > > > > > > > > > > > In any case, thanks a lot for the results! > > > > > > > > > > > > > > >> >- Significant change (meaning >10% difference > > > > > > > >> > between base and experiment) on will-it-scale > > > > > > > >> > tests in AMD. > > > > > > > >> > > > > > > > > >> >Summary of AMD will-it-scale test changes: > > > > > > > >> > > > > > > > > >> >Number of runs : 15 > > > > > > > >> >Direction : + is good > > > > > > > >> > > > > > > > >> If STDDEV grows more than mean, there is more jitter, > > > > > > > >> which is not "good". > > > > > > > > > > > > > > > > This is true. On the other hand, the mean grew way more in absolute > > > > > > > > terms than did STDDEV. So might this be a reasonable tradeoff? > > > > > > > > > > > > > > Also I'd point out that MIN of TEST is better than MAX of BASE, which means > > > > > > > there's always an improvement for this config. So jitter here means it's > > > > > > > changing between better and more better :) and not between worse and (more) > > > > > > > better. > > > > > > > > > > > > > > The annoying part of course is that for other configs it's consistently the > > > > > > > opposite. > > > > > > > > > > > > Hi Vlastimil, > > > > > > I ran my mmap stress test that runs 20000 cycles of mmapping 50 VMAs, > > > > > > faulting them in then unmapping and timing only mmap and munmap calls. > > > > > > This is not a realistic scenario but works well for A/B comparison. > > > > > > > > > > > > The numbers are below with sheaves showing a clear improvement: > > > > > > > > > > > > Baseline > > > > > > avg stdev > > > > > > mmap 2.621073 0.2525161631 > > > > > > munmap 2.292965 0.008831973052 > > > > > > total 4.914038 0.2572620923 > > > > > > > > > > > > Sheaves > > > > > > avg stdev avg_diff stdev_diff > > > > > > mmap 1.561220667 0.07748897037 -40.44% -69.31% > > > > > > munmap 2.042071 0.03603083448 -10.94% 307.96% > > > > > > total 3.603291667 0.113209047 -26.67% -55.99% > > > > > > > > > > > Could you run your test with dropping below patch? > > > > > > > > Sure, will try later today and report. > > > > > > Sheaves with [04/23] patch reverted: > > > > > > avg avg_diff > > > mmap 2.143948 -18.20% > > > munmap 2.343707 2.21% > > > total 4.487655 -8.68% > > > > > With offloading over sheaves the mmap/munmap is faster, i assume it is > > because of same objects are reused from the sheaves after reclaim. Whereas we, > > kvfree_rcu() just free them. > > Sorry, I am having trouble following where you think the speed up is > coming from. > > Can you clarify what you mean by offloading and reclaim in this context? > [1] avg stdev avg_diff stdev_diff mmap 1.561220667 0.07748897037 -40.44% -69.31% munmap 2.042071 0.03603083448 -10.94% 307.96% total 3.603291667 0.113209047 -26.67% -55.99% [1] [2] avg avg_diff mmap 2.143948 -18.20% munmap 2.343707 2.21% total 4.487655 -8.68% [2] I meant those two data results. It is comparison of freeing over or to "sheaves" and without it in the kvfree_rcu() path. -- Uladzislau Rezki