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hw-breakpoints: Use overflow handler instead of the event callback

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struct perf_event::event callback was called when a breakpoint
triggers. But this is a rather opaque callback, pretty
tied-only to the breakpoint API and not really integrated into perf
as it triggers even when we don't overflow.

We prefer to use overflow_handler() as it fits into the perf events
rules, being called only when we overflow.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>
This commit is contained in:
Frederic Weisbecker
2009-12-05 09:44:31 +01:00
parent 2f0993e0fb
commit b326e9560a
8 changed files with 48 additions and 57 deletions
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24
kernel/perf_event.c
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@ -4286,15 +4286,8 @@ static void bp_perf_event_destroy(struct perf_event *event)
static const struct pmu *bp_perf_event_init(struct perf_event *bp)
{
int err;
/*
* The breakpoint is already filled if we haven't created the counter
* through perf syscall
* FIXME: manage to get trigerred to NULL if it comes from syscalls
*/
if (!bp->callback)
err = register_perf_hw_breakpoint(bp);
else
err = __register_perf_hw_breakpoint(bp);
err = register_perf_hw_breakpoint(bp);
if (err)
return ERR_PTR(err);
@ -4390,7 +4383,7 @@ perf_event_alloc(struct perf_event_attr *attr,
struct perf_event_context *ctx,
struct perf_event *group_leader,
struct perf_event *parent_event,
perf_callback_t callback,
perf_overflow_handler_t overflow_handler,
gfp_t gfpflags)
{
const struct pmu *pmu;
@ -4433,10 +4426,10 @@ perf_event_alloc(struct perf_event_attr *attr,
event->state = PERF_EVENT_STATE_INACTIVE;
if (!callback && parent_event)
callback = parent_event->callback;
if (!overflow_handler && parent_event)
overflow_handler = parent_event->overflow_handler;
event->callback = callback;
event->overflow_handler = overflow_handler;
if (attr->disabled)
event->state = PERF_EVENT_STATE_OFF;
@ -4776,7 +4769,8 @@ err_put_context:
*/
struct perf_event *
perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
pid_t pid, perf_callback_t callback)
pid_t pid,
perf_overflow_handler_t overflow_handler)
{
struct perf_event *event;
struct perf_event_context *ctx;
@ -4793,7 +4787,7 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
}
event = perf_event_alloc(attr, cpu, ctx, NULL,
NULL, callback, GFP_KERNEL);
NULL, overflow_handler, GFP_KERNEL);
if (IS_ERR(event)) {
err = PTR_ERR(event);
goto err_put_context;