From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755063AbeD3Qpt (ORCPT ); Mon, 30 Apr 2018 12:45:49 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:43390 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754781AbeD3Qps (ORCPT ); Mon, 30 Apr 2018 12:45:48 -0400 Date: Mon, 30 Apr 2018 18:45:46 +0200 From: Oleg Nesterov To: Peter Zijlstra Cc: mingo@kernel.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, will.deacon@arm.com, mpe@ellerman.id.au, bigeasy@linutronix.de, gkohli@codeaurora.org, neeraju@codeaurora.org Subject: Re: [PATCH 2/2] sched: Introduce set_special_state() Message-ID: <20180430164545.GA10951@redhat.com> References: <20180430141751.377491406@infradead.org> <20180430142235.900370484@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180430142235.900370484@infradead.org> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/30, Peter Zijlstra wrote: > > --- a/kernel/signal.c > +++ b/kernel/signal.c > @@ -1968,7 +1968,7 @@ static void ptrace_stop(int exit_code, i > * atomic with respect to siglock and should be done after the arch > * hook as siglock is released and regrabbed across it. > */ > - set_current_state(TASK_TRACED); > + set_special_state(TASK_TRACED); Yes, but please note the comment above, we need a barrier after state = TASK_TRACED, that is why ptrace_stop() does set_current_state(), not __set_current_state(). Otherwise both patches look good to me, feel free to add Reviewed-by: Oleg Nesterov