Em Wed, Jul 12, 2023 at 07:38:58PM +0530, Ravi Bangoria escreveu:
> On 11-Jul-23 3:06 AM, Andrii Nakryiko wrote:
> > On Sun, Jul 9, 2023 at 9:05 PM Ravi Bangoria <ravi.bangoria@xxxxxxx> wrote:
> >> On 08-Jul-23 4:46 AM, Andrii Nakryiko wrote:
> >>> On Wed, Jul 5, 2023 at 9:39 PM Ravi Bangoria <ravi.bangoria@xxxxxxx> wrote:
> >>>> I'm seeing perf test failure because of commit d6e6286a12e7 ("libbpf:
> >>>> disassociate section handler on explicit bpf_program__set_type() call").
> >>> Yep, this commit would reset catch-all custom handler, which perf is
> >>> setting. I've just sent a fix upstream ([0]). And once it lands, I'll
> >>> cut a v1.2.1 libbpf bugfix release with just this fix on top of v1.2.
> >>> Can you please double-check that this patch indeed fixes the issue for
> >>> you? I tried to do this locally, but for me perf test 42 fails both at
> >>> current bpf-next, with the above commit reverted, and with my fix
> >>> applied on top. So I can't be 100% sure.
> >>> [0] https://patchwork.kernel.org/project/netdevbpf/patch/20230707231156.1711948-1-andrii@xxxxxxxxxx/
> >> Thanks. A quick test seems to be working fine.
> > Alright, thanks for confirming! I've just released v1.2.1 bug fix
> > release with just this fix on top of v1.2.
> > Thanks for reporting!
> > But given v1.2 was cut on May 1st, and the offending commit landed
> > some time late March, I wonder how did this slip through the cracks
> > and go unreported for so long? Is there something we can do to catch
> > these perf-only regressions a bit sooner?
> I guess it got slipped because that patch went in via bpf tree. Would
> it be possible to run bpf related perf tests at the time of applying
> libbpf patches? Arnaldo might have better ideas :)
Right, perhaps the libbpf CI could try building perf, preferably with
BUILD_BPF_SKEL=1, to enable these tools:
[acme@nine linux]$ ls -la tools/perf/util/bpf_skel/*.bpf.*
-rw-r--r--. 1 acme acme 5581 Jul 7 12:38 tools/perf/util/bpf_skel/bperf_cgroup.bpf.c
-rw-r--r--. 1 acme acme 1764 Jul 7 12:38 tools/perf/util/bpf_skel/bperf_follower.bpf.c
-rw-r--r--. 1 acme acme 1438 Jul 7 12:38 tools/perf/util/bpf_skel/bperf_leader.bpf.c
-rw-r--r--. 1 acme acme 2290 Jul 7 12:38 tools/perf/util/bpf_skel/bpf_prog_profiler.bpf.c
-rw-r--r--. 1 acme acme 2164 Jul 7 12:38 tools/perf/util/bpf_skel/func_latency.bpf.c
-rw-r--r--. 1 acme acme 9017 Jul 7 12:38 tools/perf/util/bpf_skel/kwork_trace.bpf.c
-rw-r--r--. 1 acme acme 10147 Jul 12 11:49 tools/perf/util/bpf_skel/lock_contention.bpf.c
-rw-r--r--. 1 acme acme 6109 Jul 7 12:38 tools/perf/util/bpf_skel/off_cpu.bpf.c
-rw-r--r--. 1 acme acme 4932 Jul 7 12:38 tools/perf/util/bpf_skel/sample_filter.bpf.c
[acme@nine linux]$
There are 'perf test' entries for the BPF support in perf that is pre
libbpf skel functionality above and as well some for the libbpf based
skel features, such as:
[root@quaco ~]# perf test -vvv contention
87: kernel lock contention analysis test :
--- start ---
test child forked, pid 213314
Testing perf lock record and perf lock contention
Testing perf lock contention --use-bpf
Testing perf lock record and perf lock contention at the same time
Testing perf lock contention --threads
Testing perf lock contention --lock-addr
Testing perf lock contention --type-filter (w/ spinlock)
Testing perf lock contention --lock-filter (w/ tasklist_lock)
Testing perf lock contention --callstack-filter (w/ unix_stream)
Testing perf lock contention --callstack-filter with task aggregation
Testing perf lock contention CSV output
test child finished with 0
---- end ----
kernel lock contention analysis test: Ok
[root@quaco ~]#
We could perhaps add support for some kind of tags to the tests, to
help run just the ones that use bpf and then you could use:
# perf test --uses bpf
At first we would just add this tag, then we would use it for other
stuff as the need arises to run just a subset of the tests.
But for now you could start perhaps with:
[root@quaco ~]# perf test LLVM ; perf test "BPF " ; perf test "lock contention"
40: LLVM search and compile :
40.1: Basic BPF llvm compile : Ok
40: LLVM search and compile :
40.1: Basic BPF llvm compile : Ok
40.3: Compile source for BPF prologue generation : Ok
40.4: Compile source for BPF relocation : Ok
42: BPF filter :
42.1: Basic BPF filtering : Ok
42.2: BPF pinning : Ok
42.3: BPF prologue generation : FAILED!
87: kernel lock contention analysis test : Ok
[root@quaco ~]#
- Arnaldo
