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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 658BEC433EF for ; Sun, 20 Feb 2022 18:14:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238730AbiBTSPP (ORCPT ); Sun, 20 Feb 2022 13:15:15 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:52118 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235997AbiBTSPP (ORCPT ); Sun, 20 Feb 2022 13:15:15 -0500 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:12e:520::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5DB23527EF for ; Sun, 20 Feb 2022 10:14:53 -0800 (PST) Received: from bigeasy by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1nLqjQ-00040h-OS; Sun, 20 Feb 2022 19:14:48 +0100 Date: Sun, 20 Feb 2022 19:14:48 +0100 From: Sebastian Andrzej Siewior To: Steven Rostedt Cc: linux-trace-devel@vger.kernel.org, Tzvetomir Stoyanov Subject: Re: trace-cmd library: Add ZSTD support. Message-ID: References: <20220219230151.56282-1-sebastian@breakpoint.cc> <20220220121143.6022d737@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220220121143.6022d737@gandalf.local.home> Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org On 2022-02-20 12:11:43 [-0500], Steven Rostedt wrote: > On Sun, 20 Feb 2022 00:01:50 +0100 > Sebastian Andrzej Siewior wrote: > > > Steven mentioned that trace-cmd recently gained compression support. I > > suggest to remove zlib since there is no real benefit to use this > > compression algorithm. > > One benefit is to just have a test case for multiple versions. And who > knows, if it is an easy implementation, perhaps there's something that > needs it in a very limited embedded environment? Does it really hurt > keeping it, even though it may never be used? Especially in embedded environment I would prefer zstd over zlib because it performance. These days, if you can allow to compile trace-cmd you should be able to include zstd, too. One downside is probably that the zstd library is larger than libz. > > It might make sense to use zstd while dumping the per-CPU data files > > disks before the trace.dat is written. It probably makes sense to use > > zstd by default instead of storing the .dat file uncompressed. > > I have a patch that does the compression by default. I'm holding off > pushing it until I finished my testing of the compressed versions. Awesome. I don't know how you make trace.dat in the end but I saw that there is one trace file per CPU first. Would it make sense to compress these before they are written to disk? > Thanks Sebastian for this update! You are welcome. > -- Steve Sebastian