Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751920AbaJSTqt (ORCPT ); Sun, 19 Oct 2014 15:46:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:2014 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751495AbaJSTqq (ORCPT ); Sun, 19 Oct 2014 15:46:46 -0400 Date: Sun, 19 Oct 2014 21:43:14 +0200 From: Oleg Nesterov To: Kirill Tkhai Cc: Kirill Tkhai , Peter Zijlstra , "linux-kernel@vger.kernel.org" , Ingo Molnar , Vladimir Davydov Subject: Re: [PATCH] sched/numa: fix unsafe get_task_struct() in task_numa_assign() Message-ID: <20141019194314.GA3434@redhat.com> References: <1413376300.24793.55.camel@tkhai> <20141017213641.GB32576@redhat.com> <4323181413620101@web21o.yandex.ru> <20141018205614.GA15934@redhat.com> <33631413674011@web7o.yandex.ru> <20141019192437.GA842@redhat.com> <20141019193744.GA3097@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141019193744.GA3097@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/19, Oleg Nesterov wrote: > > Forgot to mention... Or we can make task_struct_cachep SLAB_DESTROY_BY_RCU, > in this case ->curr (or any other "task_struct *" ponter) can not go away > under rcu_read_lock(). task_numa_compare() still needs the PF_EXITING check, > but we do not need to recheck ->curr or probe_kernel_read(). Damn, please ignore ;) we still need to recheck ->curr. Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/