hw-breakpoints: Remove stub unthrottle callback
authorFrederic Weisbecker <fweisbec@gmail.com>
Sun, 28 Feb 2010 19:51:15 +0000 (20:51 +0100)
committerFrederic Weisbecker <fweisbec@gmail.com>
Sun, 28 Feb 2010 19:51:15 +0000 (20:51 +0100)
commit1e259e0a9982078896f3404240096cbea01daca4
treec298759ae0957b014788f8c79197c90928e69623
parent388c3aab5d4f1b0bbfe2d5f47e7cd681866bc573
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>
arch/x86/kernel/hw_breakpoint.c
kernel/hw_breakpoint.c