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 X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6B186C4708F for ; Wed, 2 Jun 2021 14:11:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4EBE5613E4 for ; Wed, 2 Jun 2021 14:11:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230331AbhFBOMp (ORCPT ); Wed, 2 Jun 2021 10:12:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:50100 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230366AbhFBOLo (ORCPT ); Wed, 2 Jun 2021 10:11:44 -0400 Received: from oasis.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F3C5C613D8; Wed, 2 Jun 2021 14:10:00 +0000 (UTC) Date: Wed, 2 Jun 2021 10:09:59 -0400 From: Steven Rostedt To: "Naveen N. Rao" Cc: Torsten Duwe , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Michael Ellerman , Michal Suchanek Subject: Re: [RFC PATCH 1/6] trace/stack: Move code to save the stack trace into a separate function Message-ID: <20210602100959.185264e3@oasis.local.home> In-Reply-To: <1622626530.3j8u9fhp7h.naveen@linux.ibm.com> References: <6a8b68f8bd64f8c16d97ef943534c639781e7f77.1621577151.git.naveen.n.rao@linux.vnet.ibm.com> <20210601112824.29c5f168@oasis.local.home> <1622626530.3j8u9fhp7h.naveen@linux.ibm.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 02 Jun 2021 16:05:18 +0530 "Naveen N. Rao" wrote: > It seems to be working fine otherwise. The one limitation though is down > to how ftrace works on powerpc -- the mcount call is before a function > sets up its own stackframe. Due to this, we won't ever be able to > account for the stackframe from a leaf function -- but, that's a fairly > minor limitation. And this is true for x86 as well because it no longer uses mcount, but uses fentry instead (called before stack setup), but I figured there's not much we could do about it. -- Steve