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 90E72C5478C for ; Fri, 1 Mar 2024 04:18:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 256846B0095; Thu, 29 Feb 2024 23:18:50 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 2065D6B0096; Thu, 29 Feb 2024 23:18:50 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0CE526B0098; Thu, 29 Feb 2024 23:18:50 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id F235B6B0095 for ; Thu, 29 Feb 2024 23:18:49 -0500 (EST) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id C67E3C04A8 for ; Fri, 1 Mar 2024 04:18:49 +0000 (UTC) X-FDA: 81847164378.25.6D41A27 Received: from out-178.mta1.migadu.com (out-178.mta1.migadu.com [95.215.58.178]) by imf04.hostedemail.com (Postfix) with ESMTP id 1CB3840009 for ; Fri, 1 Mar 2024 04:18:47 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=wN9leVmh; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf04.hostedemail.com: domain of kent.overstreet@linux.dev designates 95.215.58.178 as permitted sender) smtp.mailfrom=kent.overstreet@linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1709266728; 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:dkim-signature; bh=EISxu23Q77/3CUFc4vXXHXQtBH9TF3gbFBwFkoR5QsY=; b=fzmlyjFcW94LdZUxZbDkKNy0PnU/ueVcrEJgy0K8nloGS5NnHfFT15gIpt2jyDPUOAiifm B1PpTHGIqlVBPSUwGuglzQoWJxnW1JMKL3aNXOqG+TdJomBIxmB41N5i9wIqh5D4hUvKMf nqQRh+OrvMzcuw4g2njJXAAn+yPIGnI= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=wN9leVmh; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf04.hostedemail.com: domain of kent.overstreet@linux.dev designates 95.215.58.178 as permitted sender) smtp.mailfrom=kent.overstreet@linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1709266728; a=rsa-sha256; cv=none; b=EySk6HHs0zZJlnkQZE/gkBPFrdD0IU/N/8iClOiS6TUTASN4wwY/hUa3K2qb0vPHEYozL5 T/JSAUJ8r0xs3wd15pG3gehf24vTGHAhCMJJVapYOxZs8YWxwVAEUkc/HdKMtl7xAM1UfW Age/YM830J2cyQ8C/NdOkPkkhrEwxZ0= Date: Thu, 29 Feb 2024 23:18:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1709266725; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=EISxu23Q77/3CUFc4vXXHXQtBH9TF3gbFBwFkoR5QsY=; b=wN9leVmh+Q7W3amvqJ2/HDLUCgacVtvKQB5NgJnfPoryaCmuXMM0ZJaqHoAHXqOYlQd3MH 9xyJp1icAk6oQ12UUK+uxQ/JrYSQ4I//cLxrKf0mcgTxH0z67j0GfXZrlKWRzZQ4it0Iy0 AJp12BladDMuBcbwPtTbHH310oZSs/4= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Kent Overstreet To: NeilBrown Cc: James Bottomley , Matthew Wilcox , Amir Goldstein , paulmck@kernel.org, lsf-pc@lists.linux-foundation.org, linux-mm@kvack.org, linux-fsdevel , Jan Kara Subject: Re: [Lsf-pc] [LSF/MM/BPF TOPIC] Reclamation interactions with RCU Message-ID: References: <170925937840.24797.2167230750547152404@noble.neil.brown.name> <3bykct7dzcduugy6kvp7n32sao4yavgbj2oui2rpidinst2zmn@e5qti5lkq25t> <170926614942.24797.13632376785557689080@noble.neil.brown.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <170926614942.24797.13632376785557689080@noble.neil.brown.name> X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 1CB3840009 X-Stat-Signature: widozndz53kbag14fjpqk5stugdygj6j X-HE-Tag: 1709266727-485956 X-HE-Meta: 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 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 Fri, Mar 01, 2024 at 03:09:09PM +1100, NeilBrown wrote: > No. You warn and DON'T fail the allocation. Just like lockdep warns of > possible deadlocks but lets you continue. > These will be found in development (mostly) and changed to use > __GFP_RETRY_MAYFAIL and have appropriate error-handling paths. And when an allocation happens that cannot be satisfied without killing everything off? You do realize there are _lots_ of allocations where userspace has control over the size of the allocation, via e.g. obscure ioctls that ask for a buffer to be filled?