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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 6F5FFC31E5B for ; Tue, 18 Jun 2019 17:54:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 568D6205F4 for ; Tue, 18 Jun 2019 17:54:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729285AbfFRRyP (ORCPT ); Tue, 18 Jun 2019 13:54:15 -0400 Received: from s3.sipsolutions.net ([144.76.43.62]:44620 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729586AbfFRRyO (ORCPT ); Tue, 18 Jun 2019 13:54:14 -0400 Received: by sipsolutions.net with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1hdIJ8-0003hC-LD; Tue, 18 Jun 2019 19:54:10 +0200 Message-ID: <5e7dc4f8b24431a0a6e417d64ed9c30d8cf19cb7.camel@sipsolutions.net> Subject: Re: [PATCH v2 1/2] trace-cmd: Fix crash when trace-cmd is executed with args "profile -F sleep 1" From: Johannes Berg To: Steven Rostedt , Tzvetomir Stoyanov Cc: linux-trace-devel@vger.kernel.org Date: Tue, 18 Jun 2019 19:54:05 +0200 In-Reply-To: <20190618122009.0998021e@gandalf.local.home> References: <20190605111937.17894-1-tstoyanov@vmware.com> <20190618122009.0998021e@gandalf.local.home> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5 (3.28.5-2.fc28) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-trace-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org On Tue, 2019-06-18 at 12:20 -0400, Steven Rostedt wrote: > Heads up. Johannes found a regression that this code above causes > reading a 1.7G file where the above code makes it go from reading it in > 5 seconds, to over 2 minutes! Actually, I didn't even let it finish ... It was something like 4.5 seconds to not finishing in 4.5 minutes, then I gave up. My prior version was commit 1ad32c24746. The file is 1.7G, but that's perhaps not the interesting part? A little under 620k events - by my standards, that's a small file :-) > I bisected it down to this commit (saw a small, but not so drastic > performance issue it my tests). I asked Johannes to revert the commit, > and he said that it removed the regression. With that reverted I actually see ~2 seconds now, which is 2x faster than before :-) > He said he'll report this in the Bugzilla, but we should be looking at > changing the realloc() logic. https://bugzilla.kernel.org/show_bug.cgi?id=203927 johannes