On Wed, May 13, 2020 at 11:04:25AM +0300, Alexey Budankov wrote:
>
> Implement handling of 'enable' and 'disable' control commands
> coming from control file descriptor.
>
> Signed-off-by: Alexey Budankov <alexey.budan...@linux.intel.com>
> ---
> tools/perf/builtin-record.c | 18 +++++++++++++++++-
> 1 file changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index 50dc2fe626e5..72f388623364 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -1505,6 +1505,7 @@ static int __cmd_record(struct record *rec, int argc,
> const char **argv)
> bool disabled = false, draining = false;
> int fd;
> float ratio = 0;
> + enum evlist_ctl_cmd cmd = EVLIST_CTL_CMD_UNSUPPORTED;
>
> atexit(record__sig_exit);
> signal(SIGCHLD, sig_handler);
> @@ -1802,8 +1803,23 @@ static int __cmd_record(struct record *rec, int argc,
> const char **argv)
> * Propagate error, only if there's any. Ignore positive
> * number of returned events and interrupt error.
> */
> - if (err > 0 || (err < 0 && errno == EINTR))
> + if (err > 0 || (err < 0 && errno == EINTR)) {
> err = 0;
> + if (evlist__ctlfd_process(rec->evlist, &cmd) >
> 0) {
> + switch (cmd) {
> + case EVLIST_CTL_CMD_ENABLE:
> + pr_info(EVLIST_ENABLED_MSG);
> + break;
> + case EVLIST_CTL_CMD_DISABLE:
> + pr_info(EVLIST_DISABLED_MSG);
> + break;
> + case EVLIST_CTL_CMD_ACK:
> + case EVLIST_CTL_CMD_UNSUPPORTED:
> + default:
> + break;
> + }
> + }
> + }
so this will be processed only when:
if (hits == rec->samples) {
what if there's always somethign in the buffer? will this stall?
> waking++;
>
> if (evlist__filter_pollfd(rec->evlist, POLLERR |
> POLLHUP) == 0)
evlist__filter_pollfd will trigger draining if all the maps are closed,
but there's one more fd in pollfd now, will this prevent draining?
I wonder this would fit better to the sideband thread (util/sideband_evlist.c)
so we don't disturb the main thread with another check
jirka
> --
> 2.24.1
>
>
