From: Jiri Olsa <olsajiri@gmail.com>
To: Hou Tao <houtao@huaweicloud.com>
Cc: bpf@vger.kernel.org, Martin KaFai Lau <kafai@fb.com>,
Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@chromium.org>,
Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>,
Daniel Xu <dxu@dxuuu.xyz>, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>
Subject: Re: [PATCH bpf-next 03/12] bpf: Count stats for kprobe_multi programs
Date: Tue, 5 Sep 2023 09:19:30 +0200 [thread overview]
Message-ID: <ZPbWggSZ3x0G+bx4@krava> (raw)
In-Reply-To: <6fcc4045-7a73-8ce9-0926-af5f2088d4eb@huaweicloud.com>
On Tue, Sep 05, 2023 at 02:15:49PM +0800, Hou Tao wrote:
> Hi,
>
> On 8/28/2023 3:55 PM, Jiri Olsa wrote:
> > Adding support to gather stats for kprobe_multi programs.
> >
> > We now count:
> > - missed stats due to bpf_prog_active protection (always)
> > - cnt/nsec of the bpf program execution (if kernel.bpf_stats_enabled=1)
> >
> > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> > ---
> > kernel/trace/bpf_trace.c | 8 +++++++-
> > 1 file changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> > index a7264b2c17ad..0a8685fc1eee 100644
> > --- a/kernel/trace/bpf_trace.c
> > +++ b/kernel/trace/bpf_trace.c
> > @@ -2706,18 +2706,24 @@ kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
> > .link = link,
> > .entry_ip = entry_ip,
> > };
> > + struct bpf_prog *prog = link->link.prog;
> > struct bpf_run_ctx *old_run_ctx;
> > + u64 start;
> > int err;
> >
> > if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
> > + bpf_prog_inc_misses_counter(prog);
> > err = 0;
> > goto out;
> > }
> >
> > +
> > migrate_disable();
> > rcu_read_lock();
> > old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
> > - err = bpf_prog_run(link->link.prog, regs);
> > + start = bpf_prog_start_time();
> > + err = bpf_prog_run(prog, regs);
> > + bpf_prog_update_prog_stats(prog, start);
>
> Oops, I missed the bpf_prog_run() here. It seems that bpf_prog_run() has
> already done the accounting thing, so there is no need for double
> accounting.
right, same as the other change, thanks
jirka
> > bpf_reset_run_ctx(old_run_ctx);
> > rcu_read_unlock();
> > migrate_enable();
>
next prev parent reply other threads:[~2023-09-05 7:19 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-28 7:55 [PATCH bpf-next 00/12] bpf: Add missed stats for kprobes Jiri Olsa
2023-08-28 7:55 ` [PATCH bpf-next 01/12] bpf: Move update_prog_stats to syscall object Jiri Olsa
2023-08-28 17:25 ` Alexei Starovoitov
2023-08-29 8:00 ` Jiri Olsa
2023-08-28 7:55 ` [PATCH bpf-next 02/12] bpf: Move bpf_prog_start_time to linux/filter.h Jiri Olsa
2023-09-04 13:12 ` Hou Tao
2023-08-28 7:55 ` [PATCH bpf-next 03/12] bpf: Count stats for kprobe_multi programs Jiri Olsa
2023-09-04 13:30 ` Hou Tao
2023-09-05 6:15 ` Hou Tao
2023-09-05 7:19 ` Jiri Olsa [this message]
2023-08-28 7:55 ` [PATCH bpf-next 04/12] bpf: Add missed value to kprobe_multi link info Jiri Olsa
2023-09-04 13:33 ` Hou Tao
2023-08-28 7:55 ` [PATCH bpf-next 05/12] bpf: Add missed value to kprobe perf " Jiri Olsa
2023-09-05 2:23 ` Hou Tao
2023-09-05 7:19 ` Jiri Olsa
2023-08-28 7:55 ` [PATCH bpf-next 06/12] bpf: Count missed stats in trace_call_bpf Jiri Olsa
2023-08-28 17:32 ` Alexei Starovoitov
2023-08-29 8:04 ` Jiri Olsa
2023-08-28 7:55 ` [PATCH bpf-next 07/12] bpf: Move bpf_prog_run_array down in the header file Jiri Olsa
2023-08-28 7:55 ` [PATCH bpf-next 08/12] bpf: Count run stats in bpf_prog_run_array Jiri Olsa
2023-09-05 2:40 ` Hou Tao
2023-09-05 7:19 ` Jiri Olsa
2023-08-28 7:55 ` [PATCH bpf-next 09/12] bpftool: Display missed count for kprobe_multi link Jiri Olsa
2023-08-29 16:40 ` Quentin Monnet
2023-08-30 10:46 ` Jiri Olsa
2023-08-28 7:55 ` [PATCH bpf-next 10/12] bpftool: Display missed count for kprobe perf link Jiri Olsa
2023-08-29 16:42 ` Quentin Monnet
2023-08-30 16:01 ` Jiri Olsa
2023-08-28 7:55 ` [PATCH bpf-next 11/12] selftests/bpf: Add test missed counts of perf event link kprobe Jiri Olsa
2023-09-05 3:14 ` Hou Tao
2023-08-28 7:55 ` [PATCH bpf-next 12/12] selftests/bpf: Add test recursion stats " Jiri Olsa
2023-09-05 3:23 ` Hou Tao
2023-09-05 3:30 ` [PATCH bpf-next 00/12] bpf: Add missed stats for kprobes Hou Tao
2023-09-05 7:20 ` Jiri Olsa
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