tree c298759ae0957b014788f8c79197c90928e69623
parent 388c3aab5d4f1b0bbfe2d5f47e7cd681866bc573
author Frederic Weisbecker <fweisbec@gmail.com> 1267386675 +0100
committer Frederic Weisbecker <fweisbec@gmail.com> 1267386675 +0100

hw-breakpoints: Remove stub unthrottle callback

We support event unthrottling in breakpoint events. It means
that if we have more than sysctl_perf_event_sample_rate/HZ,
perf will throttle, ignoring subsequent events until the next
tick.

So if ptrace exceeds this max rate, it will omit events, which
breaks the ptrace determinism that is supposed to report every
triggered breakpoints. This is likely to happen if we set
sysctl_perf_event_sample_rate to 1.

This patch removes support for unthrottling in breakpoint
events to break throttling and restore ptrace determinism.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: 2.6.33.x <stable@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>