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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1AA12C43334 for ; Wed, 29 Jun 2022 19:00:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229609AbiF2TA5 (ORCPT ); Wed, 29 Jun 2022 15:00:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46072 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229681AbiF2TA4 (ORCPT ); Wed, 29 Jun 2022 15:00:56 -0400 Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0BA001B781 for ; Wed, 29 Jun 2022 12:00:55 -0700 (PDT) Received: by mail-pj1-x1034.google.com with SMTP id h9-20020a17090a648900b001ecb8596e43so364474pjj.5 for ; Wed, 29 Jun 2022 12:00:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=m3AG9RdQkKvq+okquL9cMs8wgYGcDdlD+r9O3qTKjIk=; b=Y0Do0lz99V4yd5Nz6loGNeMJcHJOHwnAfpADbQ07sp+Vog8oRwNc3y4b/SzcbjvRgR 8r5qK5HsOvwFkg5X2+H1Gv/Y2QO6DKrnNA8e20WEvMdWx3HozBRx59tlcta46OXLRMAa ZX4rgGnWUHpsONLMxZezyxMn88g8TYpWP9MxBPvKohD8sW4SO5itsBkipZt1LqxyYYeL bUq1vkr8FzAgHtnoWEMVi6cSAAXVC+rBMSTpnqhzsaUrVGALJmmt9YgYqNFOBu93y1HU PlePt7BL0Ozw7v+aVVdRdfsNphsL1w+B5HS3br9PWKhgSCTZXCy99Pe7v6gDvNqHx2Kk KCsw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=m3AG9RdQkKvq+okquL9cMs8wgYGcDdlD+r9O3qTKjIk=; b=ifjNE7aniLSBFkzUbXXBFeTcsgj0bp88lla2X9S8Xmzyt0HBWFU1h0mTRvtH2pSYo7 6BwPBSqxpVjruiyhNcJmxBd+I3l7PXypYXlVq0OwPFWyNjrlyzCwfdvKBmh8i1Kr4aFQ MTmVH8P3vq2xaRyCOfGrY0CxFLPvhPSFUuP4OZIzF143Nxl4+/3nkq2bW//CFGecdb1F 6+CbHNtiW3UQiTvNCpuQIM5bFEVc6JbkLbSVk8JUCjh7eqt58UblU49ytnPlhf07l1nq 8LcmEDE75/7CZTDgjqIK09oZKjVfKLu87RTCxsSpiC+I0pCs6dnFvEcPJeEhw+H4Ob7q ssfw== X-Gm-Message-State: AJIora/Q0eiWEnjEDWvtRvEQG31TRsRtVGG6N0EqGqwJaQNfNZG/jLEe E3LsLiABEq9JtYW5Dr30VZ55Pn+qYhe9cw== X-Google-Smtp-Source: AGRyM1vuUg9v9LRXc8uTqf92k9LYfHqZPSVlOEAAitzYpiY+LZKy6uPkHW5NHxFB8qV8uBBcrBjMgw== X-Received: by 2002:a17:90a:404a:b0:1ea:e936:b69 with SMTP id k10-20020a17090a404a00b001eae9360b69mr5299705pjg.133.1656529254467; Wed, 29 Jun 2022 12:00:54 -0700 (PDT) Received: from [192.168.1.100] ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id pj4-20020a17090b4f4400b001ece6f492easm2602662pjb.44.2022.06.29.12.00.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 29 Jun 2022 12:00:53 -0700 (PDT) Message-ID: <3e15e116-ea64-501d-1292-7b2936b19681@kernel.dk> Date: Wed, 29 Jun 2022 13:00:52 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:91.0) Gecko/20100101 Thunderbird/91.10.0 Subject: Re: [PATCH 5.20 1/4] block: add bio_rewind() API Content-Language: en-US To: Kent Overstreet Cc: Ming Lei , Mike Snitzer , linux-block@vger.kernel.org, dm-devel@redhat.com, Eric Biggers , Dmitry Monakhov , "Martin K . Petersen" References: <20220624141255.2461148-1-ming.lei@redhat.com> <20220624141255.2461148-2-ming.lei@redhat.com> <20220626201458.ytn4mrix2pobm2mb@moria.home.lan> <20220628042016.wd65amvhbjuduqou@moria.home.lan> <3ad782c3-4425-9ae6-e61b-9f62f76ce9f4@kernel.dk> <20220628183247.bcaqvmnav34kp5zd@moria.home.lan> <6f8db146-d4b3-d17b-4e58-08adc0010cba@kernel.dk> <20220629184001.b66bt4jnppjquzia@moria.home.lan> From: Jens Axboe In-Reply-To: <20220629184001.b66bt4jnppjquzia@moria.home.lan> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 6/29/22 12:40 PM, Kent Overstreet wrote: > On Wed, Jun 29, 2022 at 11:16:10AM -0600, Jens Axboe wrote: >> Not sure what Christoph change you are referring to, but all the ones >> that I did to improve the init side were all backed by numbers I ran at >> that time (and most/all of the commit messages will have that data). So >> yes, it is indeed still very noticeable. Maybe not at 100K IOPS, but at >> 10M on a core it most certainly is. > > I was referring to 609be1066731fea86436f5f91022f82e592ab456. You > signed off on it, you must remember it...? I'm sure we all remember each and every commit that gets applied, particularly with such a precise description of the change. >> I'm all for having solid and maintainable code, obviously, but frivolous >> bloating of structures and more expensive setup cannot be hand waved >> away with "it doesn't matter if we touch 3 or 6 cachelines" because we >> obviously have a disagreement on that. > > I wouldn't propose inflating struct _bio_ like that. But Jens, to be > blunt - I know we have different priorities in the way we write code. > Your writeback throttling code was buggy for _ages_ and I had users > hitting deadlocks there that I pinged you about, and I could not make > heads or tails of how that code was supposed to work and not for lack > of time spent trying! OK Kent, you just wasted your 2nd chance here. Plonk. There are many rebuttals that could be made here, but I won't waste my time on it, nor would it be appropriate. Come back when you know how to act professionally. Or don't come back at all. -- Jens Axboe 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 us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3C1CFC433EF for ; Wed, 29 Jun 2022 19:03:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1656529407; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:list-id:list-help: list-unsubscribe:list-subscribe:list-post; bh=dlq04NxbxJw3JFBR6C4258zCxjsVi5cRjhsVY7mrE9k=; b=c9EZpNHOjQaG2YHAz6KA1VQ+PHagoXaw3/objeKcVQiScbVtEdZK8EKQ3HU8wYwyF2/y/y S8c+nZowdExuYLuEKoOxIF69u5v8x8BukZfirwkefoiDXRQP0FIvNaeDsu0F2njvfAkq12 yWb/r2nLvSjZLYItTNsSPNtEt6eExmY= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-136-3dkj9bvMP3S2SSrPfgT0cw-1; 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Wed, 29 Jun 2022 12:00:53 -0700 (PDT) Message-ID: <3e15e116-ea64-501d-1292-7b2936b19681@kernel.dk> Date: Wed, 29 Jun 2022 13:00:52 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:91.0) Gecko/20100101 Thunderbird/91.10.0 To: Kent Overstreet References: <20220624141255.2461148-1-ming.lei@redhat.com> <20220624141255.2461148-2-ming.lei@redhat.com> <20220626201458.ytn4mrix2pobm2mb@moria.home.lan> <20220628042016.wd65amvhbjuduqou@moria.home.lan> <3ad782c3-4425-9ae6-e61b-9f62f76ce9f4@kernel.dk> <20220628183247.bcaqvmnav34kp5zd@moria.home.lan> <6f8db146-d4b3-d17b-4e58-08adc0010cba@kernel.dk> <20220629184001.b66bt4jnppjquzia@moria.home.lan> From: Jens Axboe In-Reply-To: <20220629184001.b66bt4jnppjquzia@moria.home.lan> X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Subject: Re: [dm-devel] [PATCH 5.20 1/4] block: add bio_rewind() API X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Martin K . Petersen" , Mike Snitzer , Eric Biggers , Ming Lei , linux-block@vger.kernel.org, dm-devel@redhat.com, Dmitry Monakhov Errors-To: dm-devel-bounces@redhat.com Sender: "dm-devel" X-Scanned-By: MIMEDefang 2.85 on 10.11.54.7 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On 6/29/22 12:40 PM, Kent Overstreet wrote: > On Wed, Jun 29, 2022 at 11:16:10AM -0600, Jens Axboe wrote: >> Not sure what Christoph change you are referring to, but all the ones >> that I did to improve the init side were all backed by numbers I ran at >> that time (and most/all of the commit messages will have that data). So >> yes, it is indeed still very noticeable. Maybe not at 100K IOPS, but at >> 10M on a core it most certainly is. > > I was referring to 609be1066731fea86436f5f91022f82e592ab456. You > signed off on it, you must remember it...? I'm sure we all remember each and every commit that gets applied, particularly with such a precise description of the change. >> I'm all for having solid and maintainable code, obviously, but frivolous >> bloating of structures and more expensive setup cannot be hand waved >> away with "it doesn't matter if we touch 3 or 6 cachelines" because we >> obviously have a disagreement on that. > > I wouldn't propose inflating struct _bio_ like that. But Jens, to be > blunt - I know we have different priorities in the way we write code. > Your writeback throttling code was buggy for _ages_ and I had users > hitting deadlocks there that I pinged you about, and I could not make > heads or tails of how that code was supposed to work and not for lack > of time spent trying! OK Kent, you just wasted your 2nd chance here. Plonk. There are many rebuttals that could be made here, but I won't waste my time on it, nor would it be appropriate. Come back when you know how to act professionally. Or don't come back at all. -- Jens Axboe -- dm-devel mailing list dm-devel@redhat.com https://listman.redhat.com/mailman/listinfo/dm-devel