From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f180.google.com (mail-oi1-f180.google.com [209.85.167.180]) (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 7CDFC358363 for ; Wed, 8 Apr 2026 23:36:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.180 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775691378; cv=none; b=fQbPKKMg8oOyOi29gfkUIGzR1xU2Z2vXUiZ2MfjjSgGFVa8bFS52BPCmaEiYQhQ79m+b1lmXKHl1HNbZUQnmjHuAX+oEm9g9Fdh+eanTBGeCDaBMNp2UdTX7v8qumgB8l1ciWx0BVEpaqU5TP+6Tz2Kia/5rXwKi1L6h2aXIWpI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775691378; c=relaxed/simple; bh=ZBr1Zc2iGc55MrRjwjFgix/HVG1mDhH1y2K0uZueM3I=; h=Content-Type:From:Mime-Version:Subject:Date:Message-Id:References: Cc:In-Reply-To:To; b=rIDWWfy3rF2RHgVYu1Oy/Z6As2/YV5jpdGDI5645BAZJzrNhXYwBO3wo6o+7i/5jfS6H2S07n43wpOCT4UsXJF4n26DxsWtbxUElPZSu3oiBfExvQOBpHs8rSJo/Fke5CLM8+Ye9/qEt5IPRd1J12pxbK7IkzZcZw2+hpyYLztY= 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.20251104.gappssmtp.com header.i=@kernel-dk.20251104.gappssmtp.com header.b=0Xk0Evh/; arc=none smtp.client-ip=209.85.167.180 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.20251104.gappssmtp.com header.i=@kernel-dk.20251104.gappssmtp.com header.b="0Xk0Evh/" Received: by mail-oi1-f180.google.com with SMTP id 5614622812f47-470145d7df5so210126b6e.0 for ; Wed, 08 Apr 2026 16:36:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20251104.gappssmtp.com; s=20251104; t=1775691375; x=1776296175; darn=vger.kernel.org; h=to:in-reply-to:cc:references:message-id:date:subject:mime-version :from:content-transfer-encoding:from:to:cc:subject:date:message-id :reply-to; bh=ZBr1Zc2iGc55MrRjwjFgix/HVG1mDhH1y2K0uZueM3I=; b=0Xk0Evh/15rcD1+KMwYreNXOfW0OhdhCIdDLyEzxmu4CDD6N2C3ZHUqgxNqj3H6Xkp YDBiz0ARnWrdkz7l4rj1AlouT7qqreu7O19m3AfcbBllCb1LGNoh2/EJYTpokizUl422 NL+ALIkglo30xLRP9OkDMv6iDMaIMYAa1nS58YxhQqJgPZZ79tXMj/iMaphLdfKmjg9S SbC0g4JMKkDxv352//BnR07yrxqk2fxrPQ7Sgaeu2N+wW9xy6UasK1DFneO+0NqV3r9y YifkO4KWJkX4It8BznKrtYTyi0pYPh3CcoLcJVQZLIWds9sKcCdHJM8XrwbJRIiC1Fy4 +eXA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775691375; x=1776296175; h=to:in-reply-to:cc:references:message-id:date:subject:mime-version :from:content-transfer-encoding:x-gm-gg:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=ZBr1Zc2iGc55MrRjwjFgix/HVG1mDhH1y2K0uZueM3I=; b=Zz7Q9PR9pickzQjTmTM7T4VhDSZ0PJjrKnzPzQrJ7cPgBNMEfCFQFqS4Ya5x9qEqZc th4h3o8FMJ36wL554vlg66wppO4sRpmFTjv9ifUA2evwweBQb3P5zUyYKUdckGs5ByTw WybGn/v4UCSMh6qNq9P02RvnaTXQFFqMpmMdfsVzApVWMV3d2YyXE5n8VwczJ3HbLlxr aKtVIbBdEDZNP6bUdT9lrUGHSkstg6GxGuHgDthY17qXH8yD+3Ncs0EjH2XfN7hG3O7m DBdfgIX16haq45bpE1/oHGfTpxlCsQyhii3RbhF7WL09zM4UDrUNpkeHtur7t8OPCx7E AJ8w== X-Forwarded-Encrypted: i=1; AJvYcCWTidc2cnY5ai9ycj7K6b3dYyI5KzCggLu5OW7DAEkzOy77PqBY43cxVTX7PNOwNnaivMGoQuGB4zDQhts=@vger.kernel.org X-Gm-Message-State: AOJu0YzX0YfZfgUZT6kWrDDD72csSJh0J2fFEkSJ+jpVV8SRPjAgKLth NFS3R5EZdQhzwV5MWHzbJiNhbvNDsT7ty37Io9hAiR3sSnMiJM7M8obQPFv/bYOVCW8= X-Gm-Gg: AeBDievbx7p+9oJnpuvEzZdHmrUTTxtb9Sdcz9pyeevoNmpUJjJV12ZjWXizhtVPHZV 627stU09zToSR/8GUz00okpyuCV0MnM35BRFlt/zqqJKGz2Qr8zQfa0MkF+6eqWkvEKx3WxToEg HJy32EFa8du4+6wgjFAUpdxGdZxUDt+l5P8mqOSM0J1J+4EeqG9Eb+Q7gN7q0vct8yiujKNrMhh Pgbik3SoL1OXAduCJ4aqHzCCq+Ae4eWdeh/SnVR7kmejD6cDMZ41raX2iYDCGIb4ueH45or1KHo LCr00dHeuFKx4bWKNrrNnvoDaorqKKPZcgwuU0kUcYMZqzmnv2ENRlbmFCp90gNcbSA8avyesyd EiGE6gpiqpT3VwcTzECr0vDcbeCLNqxl9EYZfU8pYZEn5aufqgVs28BbPWtcpDVnUdqRQIYJkfU pfkEcuFnKyCPzTjW+OodjyIxw5I0F/rMJ0lF+6K7VMvnpAQVbIr6hEEV/waru+YL9SLGHH0e3zy pwp4pnjjDyBIbkl5pAj2/HRRw== X-Received: by 2002:a05:6808:1b85:b0:467:4939:9666 with SMTP id 5614622812f47-47724c79cb3mr898927b6e.47.1775691375433; Wed, 08 Apr 2026 16:36:15 -0700 (PDT) Received: from smtpclient.apple ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id 5614622812f47-46d9387a763sm12681031b6e.18.2026.04.08.16.36.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 08 Apr 2026 16:36:14 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable From: Jens Axboe Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 (1.0) Subject: Re: [PATCH RFC v4 1/3] block: add BIO_COMPLETE_IN_TASK for task-context completion Date: Wed, 8 Apr 2026 17:36:03 -0600 Message-Id: <95F28FA1-5CEF-4E80-BBB7-A429B4437D12@kernel.dk> References: <97b81868-6410-4c79-a242-679a9f04f073@columbia.edu> Cc: Matthew Wilcox , Christian Brauner , "Darrick J. Wong" , Carlos Maiolino , Alexander Viro , Jan Kara , Christoph Hellwig , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org In-Reply-To: <97b81868-6410-4c79-a242-679a9f04f073@columbia.edu> To: Tal Zussman X-Mailer: iPhone Mail (23E246) On Apr 8, 2026, at 4:51=E2=80=AFPM, Tal Zussman wrote:= >=20 > =EF=BB=BF >=20 >> On 4/8/26 3:51 PM, Jens Axboe wrote: >>> On 4/8/26 12:=E2=80=8A48 PM, Tal Zussman wrote: > On 3/25/26 4:=E2=80=8A= 14 PM, Jens Axboe wrote: >>>=20 >>> Thanks! I'm going to give Dave's llist suggestion a shot on top of >>> this as it seems like it'll simplify this nicely. Looks like that'll >>> involve turning bio::bi_next into a union with a struct llist_node. >>=20 >> Since these lists can get long, I'd keep an eye on llist reversal >> overhead there... >>=20 >=20 > Going to send v5 shortly -- tested with and without the llist reversal and= > it didn't seem to make much of a difference. This was on a single-disk VM > though, so any stress testing you could do would be very helpful. >=20 With all due respect, a single test like that isn=E2=80=99t going to be that= useful. I=E2=80=99d be wary of making that change willy nilly and just thin= king =E2=80=9Cit=E2=80=99s fine, worked fine on the one case I tested=E2=80=9D= . =E2=80=94=20 Jens Axboe