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 94BECC4332F for ; Thu, 9 Nov 2023 23:26:04 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 09A554401BB; Thu, 9 Nov 2023 18:26:04 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 049A8440183; Thu, 9 Nov 2023 18:26:04 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E2CF54401BB; Thu, 9 Nov 2023 18:26:03 -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 D4355440183 for ; Thu, 9 Nov 2023 18:26:03 -0500 (EST) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id A6E50120B54 for ; Thu, 9 Nov 2023 23:26:03 +0000 (UTC) X-FDA: 81440001006.01.ED4D2CE Received: from mail-pg1-f172.google.com (mail-pg1-f172.google.com [209.85.215.172]) by imf13.hostedemail.com (Postfix) with ESMTP id D6EB220020 for ; Thu, 9 Nov 2023 23:26:01 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b="S93A/VGS"; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf13.hostedemail.com: domain of dmitry.torokhov@gmail.com designates 209.85.215.172 as permitted sender) smtp.mailfrom=dmitry.torokhov@gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1699572361; 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=Q9Ux6J5ktMDQF6/oF6DhUm4Rz889Ag+4/KakbSomJfk=; b=RzeANpwvKVJ28dNFMgUzQnQVPKCIi8dV1Hk/dgEgc038HuhsVkk5+OpZTEMp4QQetg+Bvu RRs50UpgcZsDFJLDVbl1scegetEoZL7sDBucy/x1a8SvGb8YbcLIohq556Ibd4hr562MML onBj+Kqo8kDzny5sadBihEJ53BHEMRI= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b="S93A/VGS"; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf13.hostedemail.com: domain of dmitry.torokhov@gmail.com designates 209.85.215.172 as permitted sender) smtp.mailfrom=dmitry.torokhov@gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1699572361; a=rsa-sha256; cv=none; b=RgSz4K6bZzftAFkUiZoRGWprQyRVjTrJ8uUcCXtSnavuEsu5TwR+9ZAdDCgEIhfV/oC1SU QoiiBefE8ffyoxjOop4t/TaSS2Gt/qvcWnw7lP4XuUvUEcF9dRo83yvun/GnFI0EzjUx3c ih3CqBYBjpMoPQO2ZnedYMF0unvRSjI= Received: by mail-pg1-f172.google.com with SMTP id 41be03b00d2f7-53fa455cd94so1131371a12.2 for ; Thu, 09 Nov 2023 15:26:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1699572361; x=1700177161; darn=kvack.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=Q9Ux6J5ktMDQF6/oF6DhUm4Rz889Ag+4/KakbSomJfk=; b=S93A/VGSRn5+Av9I+ahs3vB4j7uzBjmGYlM3Uu8Y57tQZoIkmal8tiaZKAdJhnCQA1 E/DzAykvGrkQSk1sCg5vfFhE+SX0Ub1hwN22zJcUutcigWEGyduBzJfSCDISRdoLy2CU fhvMGZLUffUsqiAlE8n1UNTPtF8V2pAiK9SbuMCXWrXfAI7fRocQrBWvWbo/zOhOLWr6 jupMqqtb5UrQmdOpSI5kaV7GHJ5vH7MimuG+ySjl48OQCvapumuTQ1c9hT3IqfDmJvhI gK8tXFOMCgjcDXXOVyZeYWuwNd9jU9kEVuMeETQ+DpvzGKMLIAMok3qS+XihHLfHDdKH b74g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699572361; x=1700177161; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Q9Ux6J5ktMDQF6/oF6DhUm4Rz889Ag+4/KakbSomJfk=; b=ieOvl8TVxn3LtjoJWtT2X4tE2dG3gvON4RSWkYy1bB1sy0WkUgnvQ3kj8alPFZiOp1 EW/Rtmj+sXeaiITlB//iHByiEXguvOfZGkoU6CtlPD6eQLdjRBuTKKYd/74C7mIn0MVG MAflyFBeqNVJPQWd+NMfCfJlf69LylgRi1Gdzk7eLXfsFWgbFsfYrZDtMudFiTigrbmh YPFn4qpc7ewKgST4Fj0wJrJqZg/Nspx5LaVmsopa9sOcU3q+9g9MhQtFQIDGWM8baRpN aTmHw28XQA7NN7GQXDkPhqj8PYwwDU++M/Au8Rk1doKF8nuBybvobXJPMip3CsSxdz+L 6Clw== X-Gm-Message-State: AOJu0YwgXPzjCbM03dNB8MzhczjmUedHH4lqGa08PPUQjYzZXQd8rT4V Wa9YcjXJf6z5fUnqH4uoSIM= X-Google-Smtp-Source: AGHT+IHmqb5rrghjC404ZAdgkTo7HoXC1w11HTOeHpgssCBYEnpbsQpvtBnpm79WrOHCysPpk2B6Ww== X-Received: by 2002:a17:90b:3a88:b0:281:3fb:6df2 with SMTP id om8-20020a17090b3a8800b0028103fb6df2mr3110060pjb.22.1699572360431; Thu, 09 Nov 2023 15:26:00 -0800 (PST) Received: from google.com ([2620:15c:9d:2:c99d:e08e:5968:1b85]) by smtp.gmail.com with ESMTPSA id jx13-20020a17090b46cd00b00274b9dd8519sm300348pjb.35.2023.11.09.15.25.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Nov 2023 15:26:00 -0800 (PST) Date: Thu, 9 Nov 2023 15:25:54 -0800 From: Dmitry Torokhov To: Ankur Arora Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de, peterz@infradead.org, torvalds@linux-foundation.org, paulmck@kernel.org, linux-mm@kvack.org, x86@kernel.org, akpm@linux-foundation.org, luto@kernel.org, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, willy@infradead.org, mgorman@suse.de, jon.grimm@amd.com, bharata@amd.com, raghavendra.kt@amd.com, boris.ostrovsky@oracle.com, konrad.wilk@oracle.com, jgross@suse.com, andrew.cooper3@citrix.com, mingo@kernel.org, bristot@kernel.org, mathieu.desnoyers@efficios.com, geert@linux-m68k.org, glaubitz@physik.fu-berlin.de, anton.ivanov@cambridgegreys.com, mattst88@gmail.com, krypton@ulrich-teichert.org, rostedt@goodmis.org, David.Laight@aculab.com, richard@nod.at, mjguzik@gmail.com, Oded Gabbay , Miguel Ojeda , Jens Axboe , Minchan Kim , Sergey Senozhatsky , Sudip Mukherjee , Theodore Ts'o , "Jason A. Donenfeld" , Amit Shah , Gonglei , "Michael S. Tsirkin" , Jason Wang , "David S. Miller" , Davidlohr Bueso , Jonathan Cameron , Dave Jiang , Alison Schofield , Vishal Verma , Ira Weiny , Dan Williams , Sumit Semwal , Christian =?iso-8859-1?Q?K=F6nig?= , Andi Shyti , Ray Jui , Scott Branden , Chris Packham , Shawn Guo , Sascha Hauer , Junxian Huang , Will Deacon , Joerg Roedel , Mauro Carvalho Chehab , Srinivas Pandruvada , Hans de Goede , Ilpo =?iso-8859-1?Q?J=E4rvinen?= , Mark Gross , Finn Thain , Michael Schmitz , "James E.J. Bottomley" , "Martin K. Petersen" , Kashyap Desai , Sumit Saxena , Shivasharan S , Mark Brown , Neil Armstrong , Jens Wiklander , Alex Williamson , Helge Deller , David Hildenbrand Subject: Re: [RFC PATCH 85/86] treewide: drivers: remove cond_resched() Message-ID: References: <20231107215742.363031-1-ankur.a.arora@oracle.com> <20231107230822.371443-1-ankur.a.arora@oracle.com> <20231107230822.371443-29-ankur.a.arora@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231107230822.371443-29-ankur.a.arora@oracle.com> X-Rspam-User: X-Stat-Signature: j7qfjtixy18dy6pfjzko1ebyez6fea6u X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: D6EB220020 X-HE-Tag: 1699572361-540588 X-HE-Meta: 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 EcVR+6ER 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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: Hi Anhur, On Tue, Nov 07, 2023 at 03:08:21PM -0800, Ankur Arora wrote: > There are broadly three sets of uses of cond_resched(): > > 1. Calls to cond_resched() out of the goodness of our heart, > otherwise known as avoiding lockup splats. ... What about RCU stalls? The calls to cond_resched() in evdev.c and mousedev.c were added specifically to allow RCU to run in cases when userspace passes a large buffer and the kernel is not fully preemptable. Thanks. -- Dmitry