Re: [PATCH v2 perf,bpf 01/11] perf, bpf: consider events with attr.bpf_event as side-band events

From: Song Liu
Date: Fri Feb 15 2019 - 12:02:49 EST




> On Feb 15, 2019, at 6:14 AM, Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> wrote:
>
> Em Thu, Feb 14, 2019 at 03:58:40PM -0800, Song Liu escreveu:
>> Events with bpf_event should be considered as side-band event, as they
>> carry information about BPF programs.
>>
>> Fixes: 6ee52e2a3fe4 ("perf, bpf: Introduce PERF_RECORD_BPF_EVENT")
>> Signed-off-by: Song Liu <songliubraving@xxxxxx>
>> ---
>> kernel/events/core.c | 3 ++-
>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/kernel/events/core.c b/kernel/events/core.c
>> index 0a8dab322111..9403bdda5f8c 100644
>> --- a/kernel/events/core.c
>> +++ b/kernel/events/core.c
>> @@ -4238,7 +4238,8 @@ static bool is_sb_event(struct perf_event *event)
>> if (attr->mmap || attr->mmap_data || attr->mmap2 ||
>> attr->comm || attr->comm_exec ||
>> attr->task || attr->ksymbol ||
^ here

>> - attr->context_switch)
>> + attr->context_switch ||
>> + attr->bpf_event)
>
> What about attr->ksymbol?
>
> - Arnaldo

It is already included up there. attr->bpf_event was missed initially
because we didn't use events with bpf_event but not ksymbol. With this
set, the polling thread only has bpf_event, so we need this fix.

Thanks,
Song