From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 5CE443D3329 for ; Mon, 15 Jun 2026 16:45:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781541958; cv=none; b=Z6PXQYp4uSect0cqiLieU9DytnEEqyAJNJDgIyuCfTWfZbbLtSdSQllTkLG2NIsrA090mt9LJMTD1BMaMudXtHFFjIdHTfVFy0pcpXiWJ0LqCDSwkjtLdHJVtin9URaV9NmlUKAEVhPbj9yZEN8IE/xDCNQprJ5rzO+p6btBXBk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781541958; c=relaxed/simple; bh=2rhT4KRBA8FJ70n7B8Z4PkQDzxSg2kK1Jn2l8u+L2jw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=d2HFb3j1mZmkWDSDTZ1f7kkWR9ZLKCmnjQ3EfzJ/CZtrOPtJaMxrQoqIA2FxxgR7Fpm8klebSHiWqe4LoCEyqnlbjOr07EZ3xJrt+CkO9rQ7HNl1CsKknQ4PCb0E3U9NYgaS/FxmNPNg3DaSOmfkKWcJ+i3k+K6lP7yMfOPpb64= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=adL4St8d; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="adL4St8d" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id EDE3B2574; Mon, 15 Jun 2026 09:45:49 -0700 (PDT) Received: from e129823.arm.com (e129823.arm.com [10.2.213.3]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BEB883F905; Mon, 15 Jun 2026 09:45:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1781541954; bh=2rhT4KRBA8FJ70n7B8Z4PkQDzxSg2kK1Jn2l8u+L2jw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=adL4St8dVIpQRNnyZwBGrLv5uQei0+6Sknyap15o6sKwlZhVMg3Wz9+MSqyNsnbrL KERPyVEEF9XV2Gn1MOwoG75mznvOl+xBWWhZ9H7GBwz/Bgblg3IAYjngNGR6DM5D6R CniTN/TF6lfW1osdJ1F10MQurHGmkzQC7NDbk+PA= Date: Mon, 15 Jun 2026 17:45:49 +0100 From: Yeoreum Yun To: "David Hildenbrand (Arm)" Cc: kernel test robot , Ryan Roberts , oe-lkp@lists.linux.dev, lkp@intel.com, Andrew Morton , Muhammad Usama Anjum , Vlastimil Babka , Zi Yan , Uladzislau Rezki , Brendan Jackman , David Sterba , Johannes Weiner , Liam Howlett , Lorenzo Stoakes , Michal Hocko , Mike Rapoport , Nick Terrell , Suren Baghdasaryan , Vishal Moola , linux-mm@kvack.org Subject: Re: [linux-next:master] [vmalloc] 60ced5818f: stress-ng.shm.ops_per_sec 7.2% regression Message-ID: References: <202606022131.112319f2-lkp@intel.com> <87b8a714-e2bd-449d-9560-c181e927497a@kernel.org> Precedence: bulk X-Mailing-List: oe-lkp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87b8a714-e2bd-449d-9560-c181e927497a@kernel.org> Hi David, [...] > Looking at the original results, I spotted > > 354997 ± 14% +111.6% 751255 ± 4% meminfo.PageTables > > So we consumed twice the (process) page tables. Did you also manage to reproduce > that or do you have an explanation for that? Unfortunately not, When I tried with the reproduce scripts and see the peek usage of meminfo for Pagetable, it's almost the same (from 90000KB ~ 100,000KB), I couldn't observe the this drasmatic usage increase via this testcase. So I think this is not for this patch. > > > > > Given that the regression appears to be driven by a synthetic workload that > > combines frequent shmem page faults with repeated stack allocation/free operations, > > I do not think this is a significant concern for typical real-world workloads. > > Yeah, if it's "we have less fragmentation", I agree. Using order-2 folios for > shmem would likely similarly mitigate the problem I assume. > Agree. Thanks! -- Sincerely, Yeoreum Yun