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authorOleg Nesterov <oleg@redhat.com>2013-06-20 17:50:13 +0200
committerIngo Molnar <mingo@kernel.org>2013-06-20 17:58:55 +0200
commit7ab71f3244e9f970c29566c5a67e13d1fa38c387 (patch)
treea6bbb7e9893dc54edcf445c5a2fc75d5e27b2550 /kernel/events
parenthw_breakpoint: Simplify list/idx mess in toggle_bp_slot() paths (diff)
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hw_breakpoint: Simplify the "weight" usage in toggle_bp_slot() paths
Change toggle_bp_slot() to make "weight" negative if !enable. This way we can always use "+ weight" without additional "if (enable)" check and toggle_bp_task_slot() no longer needs this arg. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20130620155013.GA6337@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/events')
-rw-r--r--kernel/events/hw_breakpoint.c20
1 files changed, 8 insertions, 12 deletions
diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c
index dee0148dcf54..5cd4f6d9652c 100644
--- a/kernel/events/hw_breakpoint.c
+++ b/kernel/events/hw_breakpoint.c
@@ -182,7 +182,7 @@ fetch_this_slot(struct bp_busy_slots *slots, int weight)
/*
* Add a pinned breakpoint for the given task in our constraint table
*/
-static void toggle_bp_task_slot(struct perf_event *bp, int cpu, bool enable,
+static void toggle_bp_task_slot(struct perf_event *bp, int cpu,
enum bp_type_idx type, int weight)
{
/* tsk_pinned[n-1] is the number of tasks having n>0 breakpoints */
@@ -190,10 +190,7 @@ static void toggle_bp_task_slot(struct perf_event *bp, int cpu, bool enable,
int old_idx, new_idx;
old_idx = task_bp_pinned(cpu, bp, type) - 1;
- if (enable)
- new_idx = old_idx + weight;
- else
- new_idx = old_idx - weight;
+ new_idx = old_idx + weight;
if (old_idx >= 0)
tsk_pinned[old_idx]--;
@@ -211,22 +208,21 @@ toggle_bp_slot(struct perf_event *bp, bool enable, enum bp_type_idx type,
int cpu = bp->cpu;
struct task_struct *tsk = bp->hw.bp_target;
+ if (!enable)
+ weight = -weight;
+
/* Pinned counter cpu profiling */
if (!tsk) {
-
- if (enable)
- per_cpu(nr_cpu_bp_pinned[type], bp->cpu) += weight;
- else
- per_cpu(nr_cpu_bp_pinned[type], bp->cpu) -= weight;
+ per_cpu(nr_cpu_bp_pinned[type], cpu) += weight;
return;
}
/* Pinned counter task profiling */
if (cpu >= 0) {
- toggle_bp_task_slot(bp, cpu, enable, type, weight);
+ toggle_bp_task_slot(bp, cpu, type, weight);
} else {
for_each_possible_cpu(cpu)
- toggle_bp_task_slot(bp, cpu, enable, type, weight);
+ toggle_bp_task_slot(bp, cpu, type, weight);
}
if (enable)