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 CFD13C4167B for ; Thu, 9 Nov 2023 23:26:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345385AbjKIX0E (ORCPT ); Thu, 9 Nov 2023 18:26:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37130 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229613AbjKIX0D (ORCPT ); Thu, 9 Nov 2023 18:26:03 -0500 Received: from mail-pj1-x1035.google.com (mail-pj1-x1035.google.com [IPv6:2607:f8b0:4864:20::1035]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3FD92449E for ; Thu, 9 Nov 2023 15:26:01 -0800 (PST) Received: by mail-pj1-x1035.google.com with SMTP id 98e67ed59e1d1-2809414efa9so1354024a91.1 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=vger.kernel.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=jQeZQFq4hV32SvYXzh1gpq3s9d54hXWckkEJt6fKeOSDYKevsjTVvS85fNQWXVZbqk +IkBb2P81u2WwnRpE0W2JK0DIBDKuuiOEzML+x1R5dHpJnYxUhcaY4bxx9y3fOami3u4 zngGJoMWGqhRr6tt2g/G4PNwxhN6gjJjPErCSGZy43d1oAdaQi8vcOd+qHEt9bX3fceJ vG250iB+G4WUG/qGfn/c99doU3cQV4s4FGphdSQSxMIc2JKmktjtpERqoatobK3oUk3A DGK7ZsoJ/Fu+G3tV/ekVTjc6cmqpeszczz8XMKW3e73XCMNC1aAngI0RM8g0HwyqOzZP lfHg== 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=LxX/A1JfiXd680OYyIRiXU6lJlpaRO3lv9vox//8F3aJE4e5ScsuUM/EvONP+7laMU wV89EvHD75wdZfLKYMmnRO8xy7pzcDHiiiR7af5YGqUBSbNxM8Anx1HqYFy7xCxt5WZU PBCBEqEdSb6TcDjbLdjpK1CXK224MATX7U+J83her3QJPZckXt2S9nl45FD9yNDYbZ2c 1drtP+NHqugnt7ETEQg8KYsVCVicfPtFdPSG5js0x3FwDG+8DFI+sssm+3HeDG1P3cXR k0Ku+b0CdWc5H4vJ6vnUIKsR46bMsrimlR4vyZTRxbaihYUU8NwBtZNWFE9MRtocbjkN 1M6A== X-Gm-Message-State: AOJu0Yy0u4dJQuXuc6uM76wulhlOMpP7y1lpSO8hFvXJsyGZSg+nCJ2R W1aX7klMEFcR/DKEJjNZlZY= 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> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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