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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C165DC433F5 for ; Thu, 14 Oct 2021 18:07:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AC1B960EBB for ; Thu, 14 Oct 2021 18:07:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233790AbhJNSJw (ORCPT ); Thu, 14 Oct 2021 14:09:52 -0400 Received: from foss.arm.com ([217.140.110.172]:58672 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233643AbhJNSJv (ORCPT ); Thu, 14 Oct 2021 14:09:51 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 735721480; Thu, 14 Oct 2021 11:07:46 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 51FE13F66F; Thu, 14 Oct 2021 11:07:40 -0700 (PDT) Date: Thu, 14 Oct 2021 19:07:38 +0100 From: Mark Rutland To: Josh Poimboeuf Cc: Peter Zijlstra , keescook@chromium.org, jannh@google.com, linux-kernel@vger.kernel.org, vcaputo@pengaru.com, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, akpm@linux-foundation.org, christian.brauner@ubuntu.com, amistry@google.com, Kenta.Tada@sony.com, legion@kernel.org, michael.weiss@aisec.fraunhofer.de, mhocko@suse.com, deller@gmx.de, zhengqi.arch@bytedance.com, me@tobin.cc, tycho@tycho.pizza, tglx@linutronix.de, bp@alien8.de, hpa@zytor.com, axboe@kernel.dk, metze@samba.org, laijs@linux.alibaba.com, luto@kernel.org, dave.hansen@linux.intel.com, ebiederm@xmission.com, ohoono.kwon@samsung.com, kaleshsingh@google.com, yifeifz2@illinois.edu, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, vgupta@kernel.org, linux@armlinux.org.uk, will@kernel.org, guoren@kernel.org, bcain@codeaurora.org, monstr@monstr.eu, tsbogend@alpha.franken.de, nickhu@andestech.com, jonas@southpole.se, mpe@ellerman.id.au, paul.walmsley@sifive.com, hca@linux.ibm.com, ysato@users.sourceforge.jp, davem@davemloft.net, chris@zankel.net Subject: Re: [PATCH 6/7] arch: __get_wchan || STACKTRACE_SUPPORT Message-ID: <20211014180738.GC39276@lakrids.cambridge.arm.com> References: <20211008111527.438276127@infradead.org> <20211008111626.392918519@infradead.org> <20211008124052.GA976@C02TD0UTHF1T.local> <20211008161707.i3cwz6qukgcf4frj@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211008161707.i3cwz6qukgcf4frj@treble> User-Agent: Mutt/1.11.1+11 (2f07cb52) (2018-12-01) Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On Fri, Oct 08, 2021 at 09:17:07AM -0700, Josh Poimboeuf wrote: > On Fri, Oct 08, 2021 at 03:45:59PM +0200, Peter Zijlstra wrote: > > > stack_trace_save_tsk() *shouldn't* skip anything unless we've explicitly > > > told it to via skipnr, because I'd expect that > > > > It's what most archs happen to do today and is what > > stack_trace_save_tsk() as implemented using arch_stack_walk() does. > > Which is I think the closest to canonical we have. Ah; and arch_stack_walk() itself shouldn't skip anything, which gives the consistent low-level semantic I wanted. > It *is* confusing though. Even if 'nosched' may be the normally > desired behavior, stack_trace_save_tsk() should probably be named > stack_trace_save_tsk_nosched(). I agree that'd be less confusing! Josh, am I right in my understanding that the reliable stacktrace functions *shouldn't* skip sched functions, or should those similarly gain a _nosched suffix? Thanks, Mark.