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 <yuzhouj...@didichuxing.com> > > > > 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 <yuzhouj...@didichuxing.com> > > --- > > 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
