* [PATCH] perf record: Add doc for bpf event selection
@ 2019-02-01 3:06 Changbin Du
2019-02-01 8:10 ` Arnaldo Carvalho de Melo
0 siblings, 1 reply; 3+ messages in thread
From: Changbin Du @ 2019-02-01 3:06 UTC (permalink / raw)
To: peterz, mingo, acme; +Cc: jolsa, namhyung, linux-kernel, Changbin Du
Add document for how to pass bpf program with perf.
Signed-off-by: Changbin Du <changbin.du@gmail.com>
---
tools/perf/Documentation/perf-record.txt | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index d232b13ea713..0925d987cad0 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -88,6 +88,19 @@ OPTIONS
If you want to profile write accesses in [0x1000~1008), just set
'mem:0x1000/8:w'.
+ - a bpf source file or object file to select events by a bpf program.
+ The bpf program can attach to variant perf events based on section
+ names.
+
+ When passing '.c', perf searches installed LLVM to compile it into
+ object file first. Optional clang options can be pased by option
+ '--clang-opt'.
+
+ perf record --clang-opt "-DLINUX_VERSION_CODE=0x50000" \
+ -e ./tests/bpf-script-example.c
+
+ Note: '--clang-opt' must place before '--event'.
+
- a group of events surrounded by a pair of brace ("{event1,event2,...}").
Each event is separated by commas and the group should be quoted to
prevent the shell interpretation. You also need to use --group on
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] perf record: Add doc for bpf event selection
2019-02-01 3:06 [PATCH] perf record: Add doc for bpf event selection Changbin Du
@ 2019-02-01 8:10 ` Arnaldo Carvalho de Melo
2019-02-01 13:44 ` Changbin Du
0 siblings, 1 reply; 3+ messages in thread
From: Arnaldo Carvalho de Melo @ 2019-02-01 8:10 UTC (permalink / raw)
To: Changbin Du
Cc: Peter Zijlstra, Ingo Molnar, Jiri Olsa, Wang Nan, Namhyung Kim,
linux-kernel
Em Fri, Feb 01, 2019 at 03:06:41AM +0000, Changbin Du escreveu:
> Add document for how to pass bpf program with perf.
That is a good start, see some comments below.
> Signed-off-by: Changbin Du <changbin.du@gmail.com>
> ---
> tools/perf/Documentation/perf-record.txt | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
> index d232b13ea713..0925d987cad0 100644
> --- a/tools/perf/Documentation/perf-record.txt
> +++ b/tools/perf/Documentation/perf-record.txt
> @@ -88,6 +88,19 @@ OPTIONS
> If you want to profile write accesses in [0x1000~1008), just set
> 'mem:0x1000/8:w'.
>
> + - a bpf source file or object file to select events by a bpf program.
A source file (ending in .c) or a precompiled object file (ending in .o)
selects one or more BPF events.
> + The bpf program can attach to variant perf events based on section
The BPFa various
> + names.
> +
> + When passing '.c', perf searches installed LLVM to compile it into
a
> + object file first. Optional clang options can be pased by option
an
> + '--clang-opt'.
> +
> + perf record --clang-opt "-DLINUX_VERSION_CODE=0x50000" \
> + -e ./tests/bpf-script-example.c
> +
> + Note: '--clang-opt' must place before '--event'.
Please mention ~/.perfconfig, that needs a section in the
tools/perf/Documentation/perf-config.txt, for instance I have right now:
[root@quaco ~]# cat ~/.perfconfig
[llvm]
dump-obj = true
clang-opt = -g
The 'clang-opt' is the same as the command line arg you documented
above, dump object may be used to update a .o file, like:
[root@quaco ~]# vim /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c
# Do some changes, save
[root@quaco ~]# perf record -e /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c sleep 1
LLVM: dumping /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.023 MB perf.data ]
[root@quaco ~]#
And if you are up to documenting the remaining features, which I'd
encourage you, please take a look at:
tools/perf/util/llvm-utils.c
In the perf_llvm_config function. there are more things that needs
documenting, and doing a:
git blame tools/perf/util/llvm-utils.c
Helps in getting the needed explanations, for instance, the original
patch adding the .perfconfig section was this:
git show aa61fd05ca796
And it has, for instance, among others:
# kbuild directory. If not set, use /lib/modules/`uname -r`/build.
# If set to "" deliberately, skip kernel header auto-detector.
kbuild-dir = "/path/to/kernel/build"
# Options passed to 'make' when detecting kernel header options.
kbuild-opts = "ARCH=x86_64"
Thanks for working on documenting these features!
- Arnaldo
> +
> - a group of events surrounded by a pair of brace ("{event1,event2,...}").
> Each event is separated by commas and the group should be quoted to
> prevent the shell interpretation. You also need to use --group on
> --
> 2.17.1
--
- Arnaldo
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] perf record: Add doc for bpf event selection
2019-02-01 8:10 ` Arnaldo Carvalho de Melo
@ 2019-02-01 13:44 ` Changbin Du
0 siblings, 0 replies; 3+ messages in thread
From: Changbin Du @ 2019-02-01 13:44 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo
Cc: Changbin Du, Peter Zijlstra, Ingo Molnar, Jiri Olsa, Wang Nan,
Namhyung Kim, linux-kernel
Sure, please check them in v2. Thanks!
On Fri, Feb 01, 2019 at 09:10:50AM +0100, Arnaldo Carvalho de Melo wrote:
> Em Fri, Feb 01, 2019 at 03:06:41AM +0000, Changbin Du escreveu:
> > Add document for how to pass bpf program with perf.
>
> That is a good start, see some comments below.
>
> > Signed-off-by: Changbin Du <changbin.du@gmail.com>
> > ---
> > tools/perf/Documentation/perf-record.txt | 13 +++++++++++++
> > 1 file changed, 13 insertions(+)
> >
> > diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
> > index d232b13ea713..0925d987cad0 100644
> > --- a/tools/perf/Documentation/perf-record.txt
> > +++ b/tools/perf/Documentation/perf-record.txt
> > @@ -88,6 +88,19 @@ OPTIONS
> > If you want to profile write accesses in [0x1000~1008), just set
> > 'mem:0x1000/8:w'.
> >
> > + - a bpf source file or object file to select events by a bpf program.
>
> A source file (ending in .c) or a precompiled object file (ending in .o)
> selects one or more BPF events.
>
> > + The bpf program can attach to variant perf events based on section
> The BPFa various
> > + names.
> > +
> > + When passing '.c', perf searches installed LLVM to compile it into
> a
> > + object file first. Optional clang options can be pased by option
> an
> > + '--clang-opt'.
> > +
> > + perf record --clang-opt "-DLINUX_VERSION_CODE=0x50000" \
> > + -e ./tests/bpf-script-example.c
> > +
> > + Note: '--clang-opt' must place before '--event'.
>
> Please mention ~/.perfconfig, that needs a section in the
> tools/perf/Documentation/perf-config.txt, for instance I have right now:
>
> [root@quaco ~]# cat ~/.perfconfig
> [llvm]
> dump-obj = true
> clang-opt = -g
>
> The 'clang-opt' is the same as the command line arg you documented
> above, dump object may be used to update a .o file, like:
>
> [root@quaco ~]# vim /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c
>
> # Do some changes, save
>
> [root@quaco ~]# perf record -e /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c sleep 1
> LLVM: dumping /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.023 MB perf.data ]
> [root@quaco ~]#
>
> And if you are up to documenting the remaining features, which I'd
> encourage you, please take a look at:
>
> tools/perf/util/llvm-utils.c
>
> In the perf_llvm_config function. there are more things that needs
> documenting, and doing a:
>
> git blame tools/perf/util/llvm-utils.c
>
> Helps in getting the needed explanations, for instance, the original
> patch adding the .perfconfig section was this:
>
> git show aa61fd05ca796
>
> And it has, for instance, among others:
>
> # kbuild directory. If not set, use /lib/modules/`uname -r`/build.
> # If set to "" deliberately, skip kernel header auto-detector.
> kbuild-dir = "/path/to/kernel/build"
>
> # Options passed to 'make' when detecting kernel header options.
> kbuild-opts = "ARCH=x86_64"
>
> Thanks for working on documenting these features!
>
> - Arnaldo
>
>
> > +
> > - a group of events surrounded by a pair of brace ("{event1,event2,...}").
> > Each event is separated by commas and the group should be quoted to
> > prevent the shell interpretation. You also need to use --group on
> > --
> > 2.17.1
>
> --
>
> - Arnaldo
--
Cheers,
Changbin Du
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-02-01 13:45 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-02-01 3:06 [PATCH] perf record: Add doc for bpf event selection Changbin Du
2019-02-01 8:10 ` Arnaldo Carvalho de Melo
2019-02-01 13:44 ` Changbin Du
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).