From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751945AbdJFLMw (ORCPT ); Fri, 6 Oct 2017 07:12:52 -0400 Received: from merlin.infradead.org ([205.233.59.134]:52518 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751557AbdJFLMv (ORCPT ); Fri, 6 Oct 2017 07:12:51 -0400 Date: Fri, 6 Oct 2017 13:12:42 +0200 From: Peter Zijlstra To: Thomas Gleixner Cc: Chris Wilson , Daniel Vetter , Intel Graphics Development , LKML , Mika Kuoppala , Marta Lofstedt , Daniel Vetter Subject: Re: [PATCH 2/2] drm/i915: Use rcu instead of stop_machine in set_wedged Message-ID: <20171006111242.5vqwotkqxiaajsqh@hirez.programming.kicks-ass.net> References: <20171006090637.25545-1-daniel.vetter@ffwll.ch> <20171006090637.25545-2-daniel.vetter@ffwll.ch> <150728147814.14660.6817347768155085898@mail.alporthouse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 06, 2017 at 12:12:41PM +0200, Thomas Gleixner wrote: > So if you don't have a compelling technical reason to > use it, then it _is_ the wrong tool. This. stop_machine() effectively takes down _all_ CPUs for the duration of your callback. That is something you really should avoid at pretty much any cost. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [PATCH 2/2] drm/i915: Use rcu instead of stop_machine in set_wedged Date: Fri, 6 Oct 2017 13:12:42 +0200 Message-ID: <20171006111242.5vqwotkqxiaajsqh@hirez.programming.kicks-ass.net> References: <20171006090637.25545-1-daniel.vetter@ffwll.ch> <20171006090637.25545-2-daniel.vetter@ffwll.ch> <150728147814.14660.6817347768155085898@mail.alporthouse.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by gabe.freedesktop.org (Postfix) with ESMTPS id D61BC6E92F for ; Fri, 6 Oct 2017 11:12:50 +0000 (UTC) Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Thomas Gleixner Cc: Daniel Vetter , Intel Graphics Development , LKML , Daniel Vetter , Mika Kuoppala List-Id: intel-gfx@lists.freedesktop.org T24gRnJpLCBPY3QgMDYsIDIwMTcgYXQgMTI6MTI6NDFQTSArMDIwMCwgVGhvbWFzIEdsZWl4bmVy IHdyb3RlOgo+IFNvIGlmIHlvdSBkb24ndCBoYXZlIGEgY29tcGVsbGluZyB0ZWNobmljYWwgcmVh c29uIHRvCj4gdXNlIGl0LCB0aGVuIGl0IF9pc18gdGhlIHdyb25nIHRvb2wuCgpUaGlzLiBzdG9w X21hY2hpbmUoKSBlZmZlY3RpdmVseSB0YWtlcyBkb3duIF9hbGxfIENQVXMgZm9yIHRoZSBkdXJh dGlvbgpvZiB5b3VyIGNhbGxiYWNrLiBUaGF0IGlzIHNvbWV0aGluZyB5b3UgcmVhbGx5IHNob3Vs ZCBhdm9pZCBhdCBwcmV0dHkKbXVjaCBhbnkgY29zdC4KCl9fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fCkludGVsLWdmeCBtYWlsaW5nIGxpc3QKSW50ZWwtZ2Z4 QGxpc3RzLmZyZWVkZXNrdG9wLm9yZwpodHRwczovL2xpc3RzLmZyZWVkZXNrdG9wLm9yZy9tYWls bWFuL2xpc3RpbmZvL2ludGVsLWdmeAo=