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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 11EB6C77B7E for ; Fri, 26 May 2023 02:28:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=pmbJUG1pFQy53Atat6xbLW2RnK8FAQnc5UXnygmEHLY=; b=DHDKke9ymxsSfu vqJJ1T/Rb5exnwBDx4HJlTVorK7U1hSii1n+DSJq8NcRB5C8TpZND/o1YB6xV49tA6Nf2BXFxhU+A Ev6YoX/VtkUUxrJ0shBpiu+4QWwYMnJQ4NAyEojtVa0IoOagVGbkI0iQj15F24ayKmNKnfpjfCStd ZsQwrXRl5mM9dYhTXPApfHmwHEKhJ3nCSiNnLbPSbAYNQ6u/wZ1vjMZBwqYmyguCRIJLmL+9W98NF LokbKOxt+PI3Ryz3dxSL5jiYdmTQzrWCbmr62A0NJ83xKZJbQmgwAAjbh/jQAbO4boZwIuT/m83E1 wXHE1nJYPheMwIZc6NaQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1q2NCL-000ktJ-2J; Fri, 26 May 2023 02:28:57 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1q2NCH-000krd-1C; Fri, 26 May 2023 02:28:55 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 40D5264C56; Fri, 26 May 2023 02:28:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 15528C433D2; Fri, 26 May 2023 02:28:47 +0000 (UTC) Date: Thu, 25 May 2023 22:28:44 -0400 From: Steven Rostedt To: Nadav Amit Cc: "Arnd Bergmann" , "Thomas Gleixner" , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, linux-um@lists.infradead.org, Linux-Arch , linux-mm@kvack.org, "Andy Lutomirski" , "Ingo Molnar" , "Dave Hansen" , "Borislav Petkov" , x86@kernel.org, Peter Zijlstra , Nadav Amit Subject: Re: [PATCH v2 2/3] compiler: inline does not imply notrace Message-ID: <20230525222844.6a0d84f8@rorschach.local.home> In-Reply-To: <20230525210040.3637-3-namit@vmware.com> References: <20230525210040.3637-1-namit@vmware.com> <20230525210040.3637-3-namit@vmware.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230525_192853_470250_F541B16C X-CRM114-Status: GOOD ( 18.55 ) X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org On Thu, 25 May 2023 14:00:39 -0700 Nadav Amit wrote: > From: Nadav Amit > > Functions that are marked as "inline" are currently also not tracable. > This limits tracing functionality for many functions for no reason. > Apparently, this has been done for two reasons. > > First, as described in commit 5963e317b1e9d2a ("ftrace/x86: Do not > change stacks in DEBUG when calling lockdep"), it was intended to > prevent some functions that cannot be traced from being traced as these > functions were marked as inline (among others). > > Yet, this change has been done a decade ago, and according to Steven > Rostedt, ftrace should have improved and hopefully resolved nested > tracing issues by now. Arguably, if functions that should be traced - > for instance since they are used during tracing - still exist, they > should be marked as notrace explicitly. > > The second reason, which Steven raised, is that attaching "notrace" to > "inline" prevented tracing differences between different configs, which > caused various problem. This consideration is not very strong, and tying > "inline" and "notrace" does not seem very beneficial. The "inline" > keyword is just a hint, and many functions are currently not tracable > due to this reason. > > Disconnect "inline" from "notrace". FYI, I have a patch queued (still needs to go through testing) that already does this ;-) https://lore.kernel.org/all/20230502164102.1a51cdb4@gandalf.local.home/ -- Steve _______________________________________________ linux-um mailing list linux-um@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-um