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]) by smtp.lore.kernel.org (Postfix) with ESMTP id 807A4C47258 for ; Thu, 25 Jan 2024 08:10:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0AE7F280002; Thu, 25 Jan 2024 03:10:58 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 05E188D000C; Thu, 25 Jan 2024 03:10:57 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E76FE280002; Thu, 25 Jan 2024 03:10:57 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id D27A58D000C for ; Thu, 25 Jan 2024 03:10:57 -0500 (EST) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 675C3140C5D for ; Thu, 25 Jan 2024 08:10:57 +0000 (UTC) X-FDA: 81717112554.23.22D2004 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf21.hostedemail.com (Postfix) with ESMTP id 5FCEF1C000B for ; Thu, 25 Jan 2024 08:10:55 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf21.hostedemail.com: domain of hch@lst.de designates 213.95.11.211 as permitted sender) smtp.mailfrom=hch@lst.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1706170255; h=from:from: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: in-reply-to:in-reply-to:references:references; bh=lgxel5WDlQ20axG7jJBK/KwhDonprsLRs692KXWX/Vo=; b=ymOQEkwVikwNdi6pBINrQP43wuwO3VHkCE6iQIaJf4NLtZeoXYer/FI5F96NmH/cbh4wUP XZYnEgQVVBjIcAtsG72HEUmt4Xb3w929SOzjEs4fK/iCb2OG/XNx7eCe6ownLuX4IISytA /uq/HtIbYU5w71UpYW6SDv1c9te7w+o= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf21.hostedemail.com: domain of hch@lst.de designates 213.95.11.211 as permitted sender) smtp.mailfrom=hch@lst.de ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1706170255; a=rsa-sha256; cv=none; b=2RT25JWXoeFUfCBRfVNnZzgiIFZxU5YM6Y8lcW/5SBihPMqpXOJiPy31bYxmhwjnN6DH0l F0atZwLhrq4QmAFl/dJDeMa0icI0Zf4TdgaphHt0brbLkEBYws2xE2nSfyfFiEyJuJjGF+ QcNibrW+Zmy5ZMIAY4D5CzdUi1UW9/c= Received: by verein.lst.de (Postfix, from userid 2407) id E75D667373; Thu, 25 Jan 2024 09:10:50 +0100 (CET) Date: Thu, 25 Jan 2024 09:10:50 +0100 From: Christoph Hellwig To: Jens Axboe Cc: Christoph Hellwig , linux-block@vger.kernel.org, tj@kernel.org, jiangshanlai@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH, RFC] block: set noio context in submit_bio_noacct_nocheck Message-ID: <20240125081050.GA21006@lst.de> References: <20240124093941.2259199-1-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-Rspamd-Queue-Id: 5FCEF1C000B X-Rspam-User: X-Rspamd-Server: rspam02 X-Stat-Signature: di7hpk8t4yo6yzmazh5emzzjeiun5usy X-HE-Tag: 1706170255-190828 X-HE-Meta: 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 5CJG8mIU sojlSs3njwsO16TC/3wrwNflHidgaonkGmsssV/6xAbpp1zeJCC9h8o78A9a9DdJE2GZ+L4tU7V3N3enFsQKh3NiCKg== 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 Wed, Jan 24, 2024 at 08:40:28AM -0700, Jens Axboe wrote: > On 1/24/24 2:39 AM, Christoph Hellwig wrote: > > Make sure all in-line block layer submission runs in noio reclaim > > context. This is a big step towards allowing GFP_NOIO, the other > > one would be to have noio (and nofs for that matter) workqueues for > > kblockd and driver internal workqueues. > > I really don't like adding this for no good reason. Who's doing non NOIO > allocations down from this path? If there is a non-NOIO allocation right now that would be a bug, although I would not be surprised if we had a few of them. The reason to add this is a different one: The MM folks want to get rid of GFP_NOIO and GFP_NOFS and replace them by these context. And doing this in the submission path and kblockd will cover almost all of the noio context, with the rest probably covered by other workqueues. And this feels a lot less error prone than requiring every driver to annotate the context in their submission routines.