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authorFrederic Weisbecker <fweisbec@gmail.com>2010-02-28 20:51:15 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2010-04-01 16:01:15 -0700
commit65bddd361043f9e65122c39f714d3d6471c5c0e3 (patch)
tree864cc5160d7e4222507a5eb2755f95eba2e8b1ed /kernel
parent1dc877c1e87d46ba2bfaac30af5e1dde77b72d1c (diff)
downloadlwn-65bddd361043f9e65122c39f714d3d6471c5c0e3.tar.gz
lwn-65bddd361043f9e65122c39f714d3d6471c5c0e3.zip
hw-breakpoints: Remove stub unthrottle callback
commit 1e259e0a9982078896f3404240096cbea01daca4 upstream. 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: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: K.Prasad <prasad@linux.vnet.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/hw_breakpoint.c1
1 files changed, 0 insertions, 1 deletions
diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c
index 967e66143e11..4d99512ee149 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
};