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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 9A151C43381 for ; Wed, 13 Mar 2019 14:37:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6BBF02171F for ; Wed, 13 Mar 2019 14:37:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726855AbfCMOhI (ORCPT ); Wed, 13 Mar 2019 10:37:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34578 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725856AbfCMOhH (ORCPT ); Wed, 13 Mar 2019 10:37:07 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C194F300371C; Wed, 13 Mar 2019 14:37:06 +0000 (UTC) Received: from krava (unknown [10.43.17.124]) by smtp.corp.redhat.com (Postfix) with SMTP id 17D9818258; Wed, 13 Mar 2019 14:37:04 +0000 (UTC) Date: Wed, 13 Mar 2019 15:37:04 +0100 From: Jiri Olsa To: Alexey Budankov Cc: Arnaldo Carvalho de Melo , Namhyung Kim , Alexander Shishkin , Peter Zijlstra , Ingo Molnar , Andi Kleen , linux-kernel Subject: Re: [PATCH v4 0/10] perf: enable compression of record mode trace to save storage space Message-ID: <20190313143704.GC6676@krava> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Wed, 13 Mar 2019 14:37:06 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 28, 2019 at 11:35:24AM +0300, Alexey Budankov wrote: > > The patch set implements runtime trace compression (-z option) in > record mode and trace auto decompression in report and inject modes. > Streaming Zstandard (Zstd) API (zstd) is used for compression and > decompression of data that come from kernel mmaped data buffers. > > Usage of implemented -z,--compression_level=n option provides ~3-5x > avg. trace file size reduction on variety of tested workloads what > saves storage space on larger server systems where trace file size > can easily reach several tens or even hundreds of GiBs, especially > when profiling with dwarf-based stacks and tracing of context switches. > Implemented -f,--mmap-flush option can be used to avoid compressing > every single byte of data and increase compression ratio at the same > time lowering tool runtime overhead. Default option value is 1 what > is equal to the current perf record implementation. The option is > independent from -z setting and doesn't vary with compression level: > > $ tools/perf/perf record -z 1 -e cycles -- matrix.gcc > $ tools/perf/perf record --aio=1 -z 1 -e cycles -- matrix.gcc > $ tools/perf/perf record -z 1 -f 1024 -e cycles -- matrix.gcc > $ tools/perf/perf record --aio=1 -z 1 -f 1024 -e cycles -- matrix.gcc please make the 'z' option to choose some default value, so it's possible just to run: perf record -z ... to get comrpessed data.. not sure which strategy to use, probably the fastest '-z 1' as default with some warning about using that default value perhaps jirka