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perf_counter: small cleanup of the output routines

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Move the nmi argument to the _begin() function, so that _end() only needs the
handle. This allows the _begin() function to generate a wakeup on event loss.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Orig-LKML-Reference: <20090330171023.959404268@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra
2009-03-30 19:07:11 +02:00
committed by Ingo Molnar
parent 31f004df8d
commit 78d613eb12
1 changed files with 26 additions and 16 deletions
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42
kernel/perf_counter.c
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@@ -1663,10 +1663,20 @@ struct perf_output_handle {
unsigned int offset; unsigned int offset;
unsigned int head; unsigned int head;
int wakeup; int wakeup;
int nmi;
}; };
static inline void __perf_output_wakeup(struct perf_output_handle *handle)
{
if (handle->nmi)
perf_pending_queue(handle->counter);
else
perf_counter_wakeup(handle->counter);
}
static int perf_output_begin(struct perf_output_handle *handle, static int perf_output_begin(struct perf_output_handle *handle,
struct perf_counter *counter, unsigned int size) struct perf_counter *counter, unsigned int size,
int nmi)
{ {
struct perf_mmap_data *data; struct perf_mmap_data *data;
unsigned int offset, head; unsigned int offset, head;
@@ -1676,15 +1686,17 @@ static int perf_output_begin(struct perf_output_handle *handle,
if (!data) if (!data)
goto out; goto out;
handle->counter = counter;
handle->nmi = nmi;
if (!data->nr_pages) if (!data->nr_pages)
goto out; goto fail;
do { do {
offset = head = atomic_read(&data->head); offset = head = atomic_read(&data->head);
head += size; head += size;
} while (atomic_cmpxchg(&data->head, offset, head) != offset); } while (atomic_cmpxchg(&data->head, offset, head) != offset);
handle->counter = counter;
handle->data = data; handle->data = data;
handle->offset = offset; handle->offset = offset;
handle->head = head; handle->head = head;
@@ -1692,6 +1704,8 @@ static int perf_output_begin(struct perf_output_handle *handle,
return 0; return 0;
fail:
__perf_output_wakeup(handle);
out: out:
rcu_read_unlock(); rcu_read_unlock();
@@ -1733,14 +1747,10 @@ static void perf_output_copy(struct perf_output_handle *handle,
#define perf_output_put(handle, x) \ #define perf_output_put(handle, x) \
perf_output_copy((handle), &(x), sizeof(x)) perf_output_copy((handle), &(x), sizeof(x))
static void perf_output_end(struct perf_output_handle *handle, int nmi) static void perf_output_end(struct perf_output_handle *handle)
{ {
if (handle->wakeup) { if (handle->wakeup)
if (nmi) __perf_output_wakeup(handle);
perf_pending_queue(handle->counter);
else
perf_counter_wakeup(handle->counter);
}
rcu_read_unlock(); rcu_read_unlock();
} }
@@ -1750,12 +1760,12 @@ static int perf_output_write(struct perf_counter *counter, int nmi,
struct perf_output_handle handle; struct perf_output_handle handle;
int ret; int ret;
ret = perf_output_begin(&handle, counter, size); ret = perf_output_begin(&handle, counter, size, nmi);
if (ret) if (ret)
goto out; goto out;
perf_output_copy(&handle, buf, size); perf_output_copy(&handle, buf, size);
perf_output_end(&handle, nmi); perf_output_end(&handle);
out: out:
return ret; return ret;
@@ -1804,7 +1814,7 @@ static void perf_output_group(struct perf_counter *counter, int nmi)
size = sizeof(header) + counter->nr_siblings * sizeof(entry); size = sizeof(header) + counter->nr_siblings * sizeof(entry);
ret = perf_output_begin(&handle, counter, size); ret = perf_output_begin(&handle, counter, size, nmi);
if (ret) if (ret)
return; return;
@@ -1824,7 +1834,7 @@ static void perf_output_group(struct perf_counter *counter, int nmi)
perf_output_put(&handle, entry); perf_output_put(&handle, entry);
} }
perf_output_end(&handle, nmi); perf_output_end(&handle);
} }
void perf_counter_output(struct perf_counter *counter, void perf_counter_output(struct perf_counter *counter,
@@ -1869,7 +1879,7 @@ static void perf_counter_mmap_output(struct perf_counter *counter,
{ {
struct perf_output_handle handle; struct perf_output_handle handle;
int size = mmap_event->event.header.size; int size = mmap_event->event.header.size;
int ret = perf_output_begin(&handle, counter, size); int ret = perf_output_begin(&handle, counter, size, 0);
if (ret) if (ret)
return; return;
@@ -1877,7 +1887,7 @@ static void perf_counter_mmap_output(struct perf_counter *counter,
perf_output_put(&handle, mmap_event->event); perf_output_put(&handle, mmap_event->event);
perf_output_copy(&handle, mmap_event->file_name, perf_output_copy(&handle, mmap_event->file_name,
mmap_event->file_size); mmap_event->file_size);
perf_output_end(&handle, 0); perf_output_end(&handle);
} }
static int perf_counter_mmap_match(struct perf_counter *counter, static int perf_counter_mmap_match(struct perf_counter *counter,