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 1E3E8C433DB for ; Fri, 26 Feb 2021 02:56:47 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4218C64EEB for ; Fri, 26 Feb 2021 02:56:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4218C64EEB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 98B4D6B0005; Thu, 25 Feb 2021 21:56:45 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 93B426B0006; Thu, 25 Feb 2021 21:56:45 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 851366B006C; Thu, 25 Feb 2021 21:56:45 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0002.hostedemail.com [216.40.44.2]) by kanga.kvack.org (Postfix) with ESMTP id 6F43C6B0005 for ; Thu, 25 Feb 2021 21:56:45 -0500 (EST) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 3DF1618021B82 for ; Fri, 26 Feb 2021 02:56:45 +0000 (UTC) X-FDA: 77858906370.08.9446A34 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf21.hostedemail.com (Postfix) with ESMTP id 3DE84E0001B4 for ; Fri, 26 Feb 2021 02:56:41 +0000 (UTC) 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 4EF5B64EE4; Fri, 26 Feb 2021 02:56:42 +0000 (UTC) Date: Thu, 25 Feb 2021 21:56:40 -0500 From: Steven Rostedt To: Jacob Wen Cc: Linus Torvalds , Andrew Morton , Joe Perches , Christoph Lameter , Joonsoo Kim , Linux-MM , mm-commits@vger.kernel.org, Paul McKenney , Pekka Enberg , David Rientjes Subject: Re: [patch 014/173] mm, tracing: record slab name for kmem_cache_free() Message-ID: <20210225215640.51feee2f@oasis.local.home> In-Reply-To: <81645797-baee-fb17-6432-6a5cc423f09b@oracle.com> References: <20210224115824.1e289a6895087f10c41dd8d6@linux-foundation.org> <20210224200055.U7Xz47kX5%akpm@linux-foundation.org> <20210224203708.4489755a@oasis.local.home> <20210224210740.73273c7a@oasis.local.home> <5a0b6fb4-6efd-e391-45fa-cd188f181d5d@oracle.com> <20210225093128.4cd86439@gandalf.local.home> <20210225125741.4fc7e43e@gandalf.local.home> <81645797-baee-fb17-6432-6a5cc423f09b@oracle.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 X-Stat-Signature: fhii6mmghtojhgihfmih1ogqhqis6esh X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 3DE84E0001B4 Received-SPF: none (kernel.org>: No applicable sender policy available) receiver=imf21; identity=mailfrom; envelope-from=""; helo=mail.kernel.org; client-ip=198.145.29.99 X-HE-DKIM-Result: none/none X-HE-Tag: 1614308201-919904 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, 26 Feb 2021 10:02:53 +0800 Jacob Wen wrote: > Freeing a slab name generally means removing a kernel module. > See the callers of kmem_cache_destroy. > > We need to fix some of the trace events that call TP_printk with %pS > to get a symbol of a kernel module that maybe removed later. No. If the symbol is not found in the kallsyms lookup at the time of reading the trace, it will act just like a %p and print the address. Yes, it can change the reading of the trace file form one read to the next, but it's harmless, and it's been like this since ftrace was introduced back in 2009. -- Steve