From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f41.google.com (mail-ot1-f41.google.com [209.85.210.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D25511CD1EF for ; Thu, 21 Nov 2024 14:48:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.41 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732200524; cv=none; b=nBJylHmtFkMTYliNRs0CG2dRoLpXD4rQguhzJ6uxBcLrOlyx+jngMdcoq82LXvJl1jIv12SDbWu+rDcyZf6stTjo3fS4ShLDweIdkNSmGiwWHFjcKAU+6vfx5TvMXG0O+cVCROoyET1qlD7Ab78r++S0qJvvj3Yaba+6KrfeCRc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732200524; c=relaxed/simple; bh=TkBTKpH3aXj0wtalhRKKWC1rCMI58nmYToz/lj46LcQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=cIMwtX4NmL5QbHjv/OqrKjwMdh3vLgf6OTQhrRf8F+dX87RnjPG3Nw8BBvBow9MEe9/FtK+MbXrZjnmd8dIwlir0KgROtVzp8jDMwLEPWT96KStPzBuYv66V2sPbZE1iFl8TutD4xK45nEB5NaeeYrdaPKzXDAT6Jr7bd3GwXR0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk; spf=pass smtp.mailfrom=kernel.dk; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b=dKhQmlsN; arc=none smtp.client-ip=209.85.210.41 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.dk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b="dKhQmlsN" Received: by mail-ot1-f41.google.com with SMTP id 46e09a7af769-71808b6246bso484078a34.2 for ; Thu, 21 Nov 2024 06:48:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1732200521; x=1732805321; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=0/yyPh2gYADep3K00l78HVuhtV1AcQLAqad1spZDG7E=; b=dKhQmlsNmeQ7L+gqljTfmAeE4R/uO4rpKlPebt5DJx2GYlpLWVer5La8QFOOtq5Udk OCmoT5Xnccba/CZlx9atotU4GjTQB2BOLXLt7hI9eAujTCFaloyCV3B3uzIvfh83romi 7nRmXrBV7xz53tVdHJJvEw8PPTQb6p92vPX3SRORmn/6oR2M+bIKyRR7p5AoAjqOzUS+ B4rnW6LNrmEJ1h3EwLJp26RShDFH6ubI1xf0nxmai2WgI3LJHC/EZbP4SXfJhvNMiYq5 UQItt6hK45pnh9FiTPa9FaPasjN495/UKfKGFm0bZZ8fS7gy1JrII8lPlVesWjasYmMv kNPQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1732200521; x=1732805321; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=0/yyPh2gYADep3K00l78HVuhtV1AcQLAqad1spZDG7E=; b=qcd/ufAYd+VZN1r/8TqiJwntiGC0CMG0nWAg3xPy7Ewv9Blb6U3T0KLqYmgC/cCVAP WLiDX1PQfCcWtGV9RTsVMPBg4SBfG0CA1ixTbebzAe4c+KNm9FzF33X5NSNEmrcEf+O9 yPpKGb+wPwe/PBTJPJ/WK/+7lUNo3GdnjRCxEvhhNgzT2tDLfnD5AC5XJPUvyOpmuCID /iyX4ioAU0Ibjc242IF97gQhM+Zdx7PkQsoVCvZQfzApSE9RrN+5AInEpYe876V+lBMn ACR/uCdG8XgjCBG68bh0DHtyaQxXaTU3MlWvI+v3Qa1Wvj/EfusoRhXpOpld/R79LTOe 8nNg== X-Forwarded-Encrypted: i=1; AJvYcCV++Uob5bNzGh2p3QzdvoxHEFcyqhN7KB1IJRsWniOoDMGER9upUOnJNMNYqonVt5DDnnpbQ/eWv/rbYt8=@vger.kernel.org X-Gm-Message-State: AOJu0YzwRU+/OLuJ4tIcUFJRNs1dZBpelZ/teXBSwcbIDSOjLgk2Rvme xwLE3iS7JSJMTJkTEO8L5jBX7XWzNRJ2JE12782T9of2TVy7teDr2sX1X8XjciI= X-Gm-Gg: ASbGncsWcTKAxTEgUS5jbiyTXDa2aKbNRYkBTyuUvPs6kmJzQsm+lRhfF2H5svb9emw KaAYM2iSEI6VExNR2X30NxcxNg/2Uo8CyizTPrh5lAvg4HLBJvjsFBEVKqZDpQkYYP/YagYeFQV BtmoRiQWARvuvBUoIMdDjEEky6E4Y59Q759tE/hi/7DBJlNJTy0l7J1W0GsSwU4GOvY+TGhhimU 6zJKkDXsgEQDIPYlIsdJ7p+wVuyzp15ldlV+4Dv7HYJYA== X-Google-Smtp-Source: AGHT+IF3WISUvOR5rP2S/JXDHKW/JnR6H6H6uTHhtXKPM58Ro1f2seFsCNDFThU22eEt1VyFmpXGbQ== X-Received: by 2002:a05:6830:6e85:b0:709:4757:973 with SMTP id 46e09a7af769-71ab31c0cd9mr7422132a34.23.1732200520971; Thu, 21 Nov 2024 06:48:40 -0800 (PST) Received: from [192.168.1.116] ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id 46e09a7af769-71a782138b5sm4471379a34.65.2024.11.21.06.48.39 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 21 Nov 2024 06:48:40 -0800 (PST) Message-ID: <2d7aac9d-8c47-45e1-a058-35e1de80db22@kernel.dk> Date: Thu, 21 Nov 2024 07:48:39 -0700 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: [bug-report] 5-9% FIO randomwrite ext4 perf regression on 6.12.y kernel To: Christoph Hellwig Cc: Chaitanya Kulkarni , Saeed Mirzamohammadi , "linux-kernel@vger.kernel.org" , "linux-nvme@lists.infradead.org" , Ramanan Govindarajan , Sagi Grimberg , Paul Webb , Keith Busch References: <392209D9-5AC6-4FDE-8D84-FB8A82AD9AEF@oracle.com> <0cfbfcf6-08f5-4d1b-82c4-729db9198896@nvidia.com> <20241121045714.GA20680@lst.de> Content-Language: en-US From: Jens Axboe In-Reply-To: <20241121045714.GA20680@lst.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/20/24 9:57 PM, Christoph Hellwig wrote: > On Wed, Nov 20, 2024 at 06:20:12PM -0700, Jens Axboe wrote: >> There's no way that commit is involved, the test as quoted doesn't even >> touch write zeroes. Hence if there really is a regression here, then >> it's either not easily bisectable, some error was injected while >> bisecting, or the test itself is bimodal. > > ext4 actually has some weird lazy init code using write zeroes. So > if the test actually wasn't a steady state one but only run for a short > time after init, and the mentioned commit dropped the intel hack for > deallocate as write zeroes it might actually make a difference. Ah good point, I forgot about the ext4 lazy init. But any test should surely quiesce that first, not great to have background activity with that. -- Jens Axboe