Re: [PATCH] perf tools: intel-pt: fix endless record after being terminated

From: Adrian Hunter
Date: Mon Jan 13 2020 - 09:48:15 EST


On 2/01/20 9:42 am, Wei Li wrote:
> In __cmd_record(), when receiving SIGINT(ctrl + c), a done flag will
> be set and the event list will be disabled by evlist__disable() once.
>
> While in auxtrace_record.read_finish(), the related events will be
> enabled again, if they are continuous, the recording seems to be endless.
>
> If the intel_pt event is disabled, we don't enable it again here.
>
> Before the patch:
> huawei@huawei-2288H-V5:~/linux-5.5-rc4/tools/perf$ ./perf record -e \
> intel_pt//u -p 46803
> ^C^C^C^C^C^C
>
> After the patch:
> huawei@huawei-2288H-V5:~/linux-5.5-rc4/tools/perf$ ./perf record -e \
> intel_pt//u -p 48591
> ^C[ perf record: Woken up 0 times to write data ]
> Warning:
> AUX data lost 504 times out of 4816!
>
> [ perf record: Captured and wrote 2024.405 MB perf.data ]
>
> Signed-off-by: Wei Li <liwei391@xxxxxxxxxx>

All ->read_finish() implementations seem the same, so can we make a common
helper auxtrace_read_finish() and set all .read_finish = to that.

> ---
> tools/perf/arch/x86/util/intel-pt.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/tools/perf/arch/x86/util/intel-pt.c b/tools/perf/arch/x86/util/intel-pt.c
> index 20df442fdf36..1e96afcd8646 100644
> --- a/tools/perf/arch/x86/util/intel-pt.c
> +++ b/tools/perf/arch/x86/util/intel-pt.c
> @@ -1173,9 +1173,13 @@ static int intel_pt_read_finish(struct auxtrace_record *itr, int idx)
> struct evsel *evsel;
>
> evlist__for_each_entry(ptr->evlist, evsel) {
> - if (evsel->core.attr.type == ptr->intel_pt_pmu->type)
> - return perf_evlist__enable_event_idx(ptr->evlist, evsel,
> - idx);
> + if (evsel->core.attr.type == ptr->intel_pt_pmu->type) {
> + if (evsel->disabled)
> + return 0;
> + else
> + return perf_evlist__enable_event_idx(
> + ptr->evlist, evsel, idx);
> + }
> }
> return -EINVAL;
> }
>