Re: [PATCH 3/3] perf: Allow kernel filters on cpu events

From: Ingo Molnar
Date: Fri Feb 10 2017 - 03:39:51 EST



* Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx> wrote:

> While supporting file-based address filters for cpu events requires some
> extra context switch handling, kernel address filters are easy, since the
> kernel mapping is preserved across address spaces. It is also useful as
> it permits tracing scheduling paths of the kernel.
>
> This patch allows setting up kernel filters for cpu events.
>
> Signed-off-by: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
> Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> ---
> include/linux/perf_event.h | 2 ++
> kernel/events/core.c | 42 ++++++++++++++++++++++++++++--------------
> 2 files changed, 30 insertions(+), 14 deletions(-)
>
> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
> index fcb37c81ca..f4ea0600b2 100644
> --- a/include/linux/perf_event.h
> +++ b/include/linux/perf_event.h
> @@ -486,6 +486,7 @@ struct perf_addr_filter {
> * @list: list of filters for this event
> * @lock: spinlock that serializes accesses to the @list and event's
> * (and its children's) filter generations.
> + * @nr_file_filters: number of file-based filters

I've applied the patch, but please for heaven's sake, when you add such a long,
long argument name, at minimum re-tabulate the documentation section to look good
again ...

Thanks,

Ingo