On 08/06, Jiri Olsa wrote:
>
> We need to change the breakpoint even if the attr with
> new fields has disabled set to true.
Agreed... The patch looks fine to me, but I have a question
> int modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr
> *attr)
> {
> + int err;
> +
> /*
> * modify_user_hw_breakpoint can be invoked with IRQs disabled and
> hence it
> * will not be possible to raise IPIs that invoke __perf_event_disable.
> @@ -520,11 +522,11 @@ int modify_user_hw_breakpoint(struct perf_event *bp,
> struct perf_event_attr *att
> else
> perf_event_disable(bp);
>
> - if (!attr->disabled) {
> - int err = modify_user_hw_breakpoint_check(bp, attr, false);
> + err = modify_user_hw_breakpoint_check(bp, attr, false);
> + if (err)
> + return err;
>
> - if (err)
> - return err;
> + if (!attr->disabled) {
> perf_event_enable(bp);
> bp->attr.disabled = 0;
Afaics you do not need to clear attr.disabled, modify_user_hw_breakpoint_check()
updates it if err = 0. So I think
if (!bp->attr.disabled)
perf_event_enable(bp);
will look a bit better.
But, with or without this fix, shouldn't we set .disabled = 1 if modify_()
fails?
IIUC this doesn't matter, bp->attr.disabled is not really used anyway, but
looks a
bit confusing.
Oleg.
