From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joonas Lahtinen Subject: Re: [PATCH] [RFC] kernel/cpu: Use lockref for online CPU reference counting Date: Wed, 17 Feb 2016 14:47:31 +0200 Message-ID: <1455713251.5622.9.camel@linux.intel.com> References: <1455539803-13913-1-git-send-email-joonas.lahtinen@linux.intel.com> <20160215141755.GG6357@twins.programming.kicks-ass.net> <20160215170618.GL6375@twins.programming.kicks-ass.net> <1455612576.4977.11.camel@linux.intel.com> <20160216091440.GT6357@twins.programming.kicks-ass.net> <1455619863.4977.29.camel@linux.intel.com> <20160216110732.GU6357@twins.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTP id C510A89F73 for ; Wed, 17 Feb 2016 12:47:33 +0000 (UTC) In-Reply-To: <20160216110732.GU6357@twins.programming.kicks-ass.net> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Peter Zijlstra , Oleg Nesterov Cc: "Gautham R. Shenoy" , Intel graphics driver community testing & development , Linux kernel development , David Hildenbrand , "Paul E. McKenney" , Ingo Molnar List-Id: intel-gfx@lists.freedesktop.org T24gdGksIDIwMTYtMDItMTYgYXQgMTI6MDcgKzAxMDAsIFBldGVyIFppamxzdHJhIHdyb3RlOgo+ IE9uIFR1ZSwgRmViIDE2LCAyMDE2IGF0IDEyOjUxOjAzUE0gKzAyMDAsIEpvb25hcyBMYWh0aW5l biB3cm90ZToKPiA+IFF1b3RpbmcgbXkgb3JpZ2luYWwgcGF0Y2g7Cj4gPiAKPiA+ICJTZWUgdGhl IEJ1Z3ppbGxhIGxpbmsgZm9yIG1vcmUgZGV0YWlscy4KPiAKPiBJZiBpdHMgbm90IGluIHRoZSBD aGFuZ2Vsb2cgaXQgZG9lc24ndCBleGlzdC4gUGF0Y2hlcyBzaG91bGQgYmUgc2VsZgo+IGNvbnRh aW5lZCBhbmQgbm90IHJlZmVyIHRvIGV4dGVybmFsIHNvdXJjZXMgZm9yIGNyaXRpY2FsIGluZm9y bWF0aW9uLgoKVGhlIGV4YWN0IGxvY2tpbmcgY2FzZSBpbiBDUFVmcmVxIGRyaXZlcnMgY2F1c2lu ZyBhIHNwbGF0IGlzIGRlc2NyaWJlZAppbiB0aGUgcGF0Y2guIERldGFpbHMgd2VyZSBhbHJlYWR5 IGluY2x1ZGVkLCB0aGF0J3Mgd2h5IHRlcm0gIm1vcmUKZGV0YWlscyIgd2FzIHVzZWQuCgpUaGlz IGlzIG5vdCBleGFjdGx5IHRha2luZyB1cyBjbG9zZXIgdG8gYSBmaXgsIHNvIEknZCByYXRoZXIg bGlrZSB0bwpkaXNjdXNzIGFib3V0IHRoZSBwb3NzaWJpbGl0eSBvZiBhZGRpbmcgb25lIG1vcmUg bWVtYmVyIHRvIHRhc2tfc3RydWN0LgpJIGFkZGVkIE9sZWcgYXMgQ0MgdG8gY2F0Y2ggaGlzIGF0 dGVudGlvbiB0byByZS1ldmFsdWF0ZSBiYXNlZCBvbiB0aGUKcHJldmlvdXMgZGlzY3Vzc2lvbiBp biB0aGlzIHRocmVhZC4KClJlZ2FyZHMsIEpvb25hcwoKLS0gCkpvb25hcyBMYWh0aW5lbgpPcGVu IFNvdXJjZSBUZWNobm9sb2d5IENlbnRlcgpJbnRlbCBDb3Jwb3JhdGlvbgoKX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KSW50ZWwtZ2Z4IG1haWxpbmcgbGlz dApJbnRlbC1nZnhAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlzdHMuZnJlZWRlc2t0 b3Aub3JnL21haWxtYW4vbGlzdGluZm8vaW50ZWwtZ2Z4Cg== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965292AbcBQMrf (ORCPT ); Wed, 17 Feb 2016 07:47:35 -0500 Received: from mga03.intel.com ([134.134.136.65]:60476 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965076AbcBQMre (ORCPT ); Wed, 17 Feb 2016 07:47:34 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.22,460,1449561600"; d="scan'208";a="904474137" Message-ID: <1455713251.5622.9.camel@linux.intel.com> Subject: Re: [PATCH] [RFC] kernel/cpu: Use lockref for online CPU reference counting From: Joonas Lahtinen To: Peter Zijlstra , Oleg Nesterov Cc: Intel graphics driver community testing & development , Linux kernel development , Ingo Molnar , David Hildenbrand , "Paul E. McKenney" , "Gautham R. Shenoy" , Chris Wilson , Daniel Vetter Date: Wed, 17 Feb 2016 14:47:31 +0200 In-Reply-To: <20160216110732.GU6357@twins.programming.kicks-ass.net> References: <1455539803-13913-1-git-send-email-joonas.lahtinen@linux.intel.com> <20160215141755.GG6357@twins.programming.kicks-ass.net> <20160215170618.GL6375@twins.programming.kicks-ass.net> <1455612576.4977.11.camel@linux.intel.com> <20160216091440.GT6357@twins.programming.kicks-ass.net> <1455619863.4977.29.camel@linux.intel.com> <20160216110732.GU6357@twins.programming.kicks-ass.net> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.18.4 (3.18.4-1.fc23) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On ti, 2016-02-16 at 12:07 +0100, Peter Zijlstra wrote: > On Tue, Feb 16, 2016 at 12:51:03PM +0200, Joonas Lahtinen wrote: > > Quoting my original patch; > > > > "See the Bugzilla link for more details. > > If its not in the Changelog it doesn't exist. Patches should be self > contained and not refer to external sources for critical information. The exact locking case in CPUfreq drivers causing a splat is described in the patch. Details were already included, that's why term "more details" was used. This is not exactly taking us closer to a fix, so I'd rather like to discuss about the possibility of adding one more member to task_struct. I added Oleg as CC to catch his attention to re-evaluate based on the previous discussion in this thread. Regards, Joonas -- Joonas Lahtinen Open Source Technology Center Intel Corporation