| Message ID | 20240703223035.2024586-1-namhyung@kernel.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | perf record: Use a pinned BPF program for filter | expand |
Ping! On Wed, Jul 3, 2024 at 3:30 PM Namhyung Kim <namhyung@kernel.org> wrote: > > Hello, > > This is to support the unprivileged BPF filter for profiling per-task events. > Until now only root (or any user with CAP_BPF) can use the filter and we > cannot add a new unprivileged BPF program types. After talking with the BPF > folks at LSF/MM/BPF 2024, I was told that this is the way to go. Finally I > managed to make it working with pinned BPF objects. :) > > v3 changes) > * rebased onto latest perf-tools-next > > v2 changes) > * rebased onto Ian's UID/GID (non-sample data based) filter term change > * support separate lost counts for each use case > * update the test case to allow normal users (if supported) > > > This only supports the per-task mode for normal users and root still uses > its own instance of the same BPF program - not shared with other users. > But it requires the one-time setup (by root) before using it by normal users > like below. > > $ sudo perf record --setup-filter pin > > This will load the BPF program and maps and pin them in the BPF-fs. Then > normal users can use the filter. > > $ perf record -o- -e cycles:u --filter 'period < 10000' perf test -w noploop | perf script -i- > [ perf record: Woken up 1 times to write data ] > [ perf record: Captured and wrote 0.011 MB - ] > perf 759982 448227.214189: 1 cycles:u: 7f153719f4d0 _start+0x0 (/usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2) > perf 759982 448227.214195: 1 cycles:u: 7f153719f4d0 _start+0x0 (/usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2) > perf 759982 448227.214196: 7 cycles:u: 7f153719f4d0 _start+0x0 (/usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2) > perf 759982 448227.214196: 223 cycles:u: 7f153719f4d0 _start+0x0 (/usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2) > perf 759982 448227.214198: 9475 cycles:u: ffffffff8ee012a0 [unknown] ([unknown]) > perf 759982 448227.548608: 1 cycles:u: 559a9f03c81c noploop+0x5c (/home/namhyung/linux/tools/perf/perf) > perf 759982 448227.548611: 1 cycles:u: 559a9f03c81c noploop+0x5c (/home/namhyung/linux/tools/perf/perf) > perf 759982 448227.548612: 12 cycles:u: 559a9f03c81c noploop+0x5c (/home/namhyung/linux/tools/perf/perf) > perf 759982 448227.548613: 466 cycles:u: 559a9f03c81c noploop+0x5c (/home/namhyung/linux/tools/perf/perf) > > It's also possible to unload (and unpin, of course) using this command: > > $ sudo perf record --setup-filter unpin > > The code is avaiable in 'perf/pinned-filter-v3' branch at > > git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git > > Thanks, > Namhyung > > > Namhyung Kim (8): > perf bpf-filter: Make filters map a single entry hashmap > perf bpf-filter: Pass 'target' to perf_bpf_filter__prepare() > perf bpf-filter: Split per-task filter use case > perf bpf-filter: Support pin/unpin BPF object > perf bpf-filter: Support separate lost counts for each filter > perf record: Fix a potential error handling issue > perf record: Add --setup-filter option > perf test: Update sample filtering test > > tools/perf/Documentation/perf-record.txt | 5 + > tools/perf/builtin-record.c | 23 +- > tools/perf/builtin-stat.c | 2 +- > tools/perf/builtin-top.c | 2 +- > tools/perf/builtin-trace.c | 2 +- > tools/perf/tests/shell/record_bpf_filter.sh | 13 +- > tools/perf/util/bpf-filter.c | 406 +++++++++++++++++-- > tools/perf/util/bpf-filter.h | 19 +- > tools/perf/util/bpf_skel/sample-filter.h | 2 + > tools/perf/util/bpf_skel/sample_filter.bpf.c | 75 +++- > tools/perf/util/evlist.c | 5 +- > tools/perf/util/evlist.h | 4 +- > 12 files changed, 483 insertions(+), 75 deletions(-) > > -- > 2.45.2.803.g4e1b14247a-goog > >
Hello, This is to support the unprivileged BPF filter for profiling per-task events. Until now only root (or any user with CAP_BPF) can use the filter and we cannot add a new unprivileged BPF program types. After talking with the BPF folks at LSF/MM/BPF 2024, I was told that this is the way to go. Finally I managed to make it working with pinned BPF objects. :) v3 changes) * rebased onto latest perf-tools-next v2 changes) * rebased onto Ian's UID/GID (non-sample data based) filter term change * support separate lost counts for each use case * update the test case to allow normal users (if supported) This only supports the per-task mode for normal users and root still uses its own instance of the same BPF program - not shared with other users. But it requires the one-time setup (by root) before using it by normal users like below. $ sudo perf record --setup-filter pin This will load the BPF program and maps and pin them in the BPF-fs. Then normal users can use the filter. $ perf record -o- -e cycles:u --filter 'period < 10000' perf test -w noploop | perf script -i- [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.011 MB - ] perf 759982 448227.214189: 1 cycles:u: 7f153719f4d0 _start+0x0 (/usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2) perf 759982 448227.214195: 1 cycles:u: 7f153719f4d0 _start+0x0 (/usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2) perf 759982 448227.214196: 7 cycles:u: 7f153719f4d0 _start+0x0 (/usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2) perf 759982 448227.214196: 223 cycles:u: 7f153719f4d0 _start+0x0 (/usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2) perf 759982 448227.214198: 9475 cycles:u: ffffffff8ee012a0 [unknown] ([unknown]) perf 759982 448227.548608: 1 cycles:u: 559a9f03c81c noploop+0x5c (/home/namhyung/linux/tools/perf/perf) perf 759982 448227.548611: 1 cycles:u: 559a9f03c81c noploop+0x5c (/home/namhyung/linux/tools/perf/perf) perf 759982 448227.548612: 12 cycles:u: 559a9f03c81c noploop+0x5c (/home/namhyung/linux/tools/perf/perf) perf 759982 448227.548613: 466 cycles:u: 559a9f03c81c noploop+0x5c (/home/namhyung/linux/tools/perf/perf) It's also possible to unload (and unpin, of course) using this command: $ sudo perf record --setup-filter unpin The code is avaiable in 'perf/pinned-filter-v3' branch at git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git Thanks, Namhyung Namhyung Kim (8): perf bpf-filter: Make filters map a single entry hashmap perf bpf-filter: Pass 'target' to perf_bpf_filter__prepare() perf bpf-filter: Split per-task filter use case perf bpf-filter: Support pin/unpin BPF object perf bpf-filter: Support separate lost counts for each filter perf record: Fix a potential error handling issue perf record: Add --setup-filter option perf test: Update sample filtering test tools/perf/Documentation/perf-record.txt | 5 + tools/perf/builtin-record.c | 23 +- tools/perf/builtin-stat.c | 2 +- tools/perf/builtin-top.c | 2 +- tools/perf/builtin-trace.c | 2 +- tools/perf/tests/shell/record_bpf_filter.sh | 13 +- tools/perf/util/bpf-filter.c | 406 +++++++++++++++++-- tools/perf/util/bpf-filter.h | 19 +- tools/perf/util/bpf_skel/sample-filter.h | 2 + tools/perf/util/bpf_skel/sample_filter.bpf.c | 75 +++- tools/perf/util/evlist.c | 5 +- tools/perf/util/evlist.h | 4 +- 12 files changed, 483 insertions(+), 75 deletions(-)