From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Olsa Subject: Re: [PATCH] perf record: Add support to collect callchains from kernel or user space only. Date: Thu, 6 Jun 2019 16:46:14 +0200 Message-ID: <20190606144614.GC12056@krava> References: <1559222962-22891-1-git-send-email-ufo19890607@gmail.com> <20190606142644.GA21245@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190606142644.GA21245@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Arnaldo Carvalho de Melo Cc: ufo19890607 , peterz@infradead.org, mingo@redhat.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, dsahern@gmail.com, namhyung@kernel.org, milian.wolff@kdab.com, arnaldo.melo@gmail.com, yuzhoujian@didichuxing.com, adrian.hunter@intel.com, wangnan0@huawei.com, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, acme@redhat.com List-Id: linux-perf-users.vger.kernel.org On Thu, Jun 06, 2019 at 11:26:44AM -0300, Arnaldo Carvalho de Melo wrote: > Em Thu, May 30, 2019 at 02:29:22PM +0100, ufo19890607 escreveu: > > From: yuzhoujian > > > > One can just record callchains in the kernel or user space with > > this new options. We can use it together with "--all-kernel" options. > > This two options is used just like print_stack(sys) or print_ustack(usr) > > for systemtap. > > > > Show below is the usage of this new option combined with "--all-kernel" > > options. > > 1. Configure all used events to run in kernel space and just > > collect kernel callchains. > > $ perf record -a -g --all-kernel --kernel-callchains > > 2. Configure all used events to run in kernel space and just > > collect user callchains. > > $ perf record -a -g --all-kernel --user-callchains > > > > Signed-off-by: yuzhoujian > > --- > > tools/perf/Documentation/perf-record.txt | 6 ++++++ > > tools/perf/builtin-record.c | 4 ++++ > > tools/perf/perf.h | 2 ++ > > tools/perf/util/evsel.c | 4 ++++ > > 4 files changed, 16 insertions(+) > > > > diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt > > index de269430720a..b647eb3db0c6 100644 > > --- a/tools/perf/Documentation/perf-record.txt > > +++ b/tools/perf/Documentation/perf-record.txt > > @@ -490,6 +490,12 @@ Configure all used events to run in kernel space. > > --all-user:: > > Configure all used events to run in user space. > > > > +--kernel-callchains:: > > +Collect callchains from kernel space. > > Ok, changing this to: > > Collect callchains only from kernel space. I.e. this option sets > perf_event_attr.exclude_callchain_user to 1, > perf_event_attr.exclude_callchain_kernel to 0. > > > + > > +--user-callchains:: > > +Collect callchains from user space. > > And this one to: > Collect callchains only from user space. I.e. this option sets > > perf_event_attr.exclude_callchain_kernel to 1, > perf_event_attr.exclude_callchain_user to 0. > > > So that the user don't try using: > > pref record --user-callchains --kernel-callchains > > expecting to get both user and kernel callchains and instead gets > nothing. good catch.. we should add the logic to keep both (default) in this case.. so do nothing ;-) jirka