From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754069AbbIJC0r (ORCPT ); Wed, 9 Sep 2015 22:26:47 -0400 Received: from mail-pa0-f50.google.com ([209.85.220.50]:34482 "EHLO mail-pa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752642AbbIJC0l (ORCPT ); Wed, 9 Sep 2015 22:26:41 -0400 Date: Thu, 10 Sep 2015 11:23:25 +0900 From: Namhyung Kim To: "Wangnan (F)" Cc: Arnaldo Carvalho de Melo , Ingo Molnar , Peter Zijlstra , Jiri Olsa , LKML , Masami Hiramatsu , pi3orama@163.com Subject: Re: [PATCH v2 1/5] perf probe: Split add_perf_probe_events() Message-ID: <20150910022325.GA32720@danjae.kornet> References: <1441368963-11565-1-git-send-email-namhyung@kernel.org> <55EBEF99.8010506@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <55EBEF99.8010506@huawei.com> User-Agent: Mutt/1.5.23+102 (2ca89bed6448) (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Sep 06, 2015 at 03:47:37PM +0800, Wangnan (F) wrote: > Hi Namhyung, Hi, > > Thanks for this patchset. > > Could you plase have a look at patch 5/27 and 6/27 in my newest pull > request? > These 2 patches utilize new probing API to create probe point and collect > probe_trace_events. I'm not very sure I fully understand your design > principle, > especially the cleanup part, because I can see different functions dealing > with > cleanup: > > cleanup_perf_probe_events > del_perf_probe_events > clear_perf_probe_event > clear_probe_trace_event > > But non of them works perfectly for me. The cleanup_perf_probe_events() is just to keep the existing logic as long as possible. But I think it needs to call clear_perf_probe_event(). The del_perf_probe_events() uses strfilter, but I think it can be problematic if other instances or users are using similar events at the same time. So for your case, IMHO it'd better keeping the perf/trace events after probing and reusing the events for unprobing. I'll take a look at it. > > In bpf_prog_priv__clear() function of 6/27, I copied some code from > cleanup_perf_probe_events(), because I think when destroying bpf programs, > the probe_trace_events should also be cleanuped, but we don't need call > exit_symbol_maps() many times, because we are in 'perf record', and not > sure whether other parts of perf need symbol maps. Otherwise I think > directly > calling cleanup_perf_probe_events() sould be better. Yeah, I also think exit_symbol_maps() should not be a part of the cleanup. I'll send a patch soon. > > You can find patch from: > > http://lkml.kernel.org/n/1441523623-152703-6-git-send-email-wangnan0@huawei.com > > http://lkml.kernel.org/n/1441523623-152703-7-git-send-email-wangnan0@huawei.com Thanks for your work! Namhyung