Commit-ID: 1e259e0a9982078896f3404240096cbea01daca4
Gitweb: http://git.kernel.org/tip/1e259e0a9982078896f3404240096cbea01daca4
Author: Frederic Weisbecker <fweisbec@xxxxxxxxx>
AuthorDate: Sun, 28 Feb 2010 20:51:15 +0100
Committer: Frederic Weisbecker <fweisbec@xxxxxxxxx>
CommitDate: Sun, 28 Feb 2010 20:51:15 +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@xxxxxxxxx>
Cc: 2.6.33.x <stable@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: K.Prasad <prasad@xxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
---
arch/x86/kernel/hw_breakpoint.c | 5 -----
kernel/hw_breakpoint.c | 1 -
2 files changed, 0 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c
index bb6006e..1e8cead 100644
--- a/arch/x86/kernel/hw_breakpoint.c
+++ b/arch/x86/kernel/hw_breakpoint.c
@@ -531,8 +531,3 @@ void hw_breakpoint_pmu_read(struct perf_event *bp)
{
/* TODO */
}
-
-void hw_breakpoint_pmu_unthrottle(struct perf_event *bp)
-{
- /* TODO */
-}
diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c
index 967e661..4d99512 100644
--- a/kernel/hw_breakpoint.c
+++ b/kernel/hw_breakpoint.c
@@ -489,5 +489,4 @@ struct pmu perf_ops_bp = {
.enable = arch_install_hw_breakpoint,
.disable = arch_uninstall_hw_breakpoint,
.read = hw_breakpoint_pmu_read,
- .unthrottle = hw_breakpoint_pmu_unthrottle
};
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