From 78d613eb129fc4edf0e2cabfcc6a4c5285482d21 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 30 Mar 2009 19:07:11 +0200 Subject: [PATCH] perf_counter: small cleanup of the output routines 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 Acked-by: Paul Mackerras Orig-LKML-Reference: <20090330171023.959404268@chello.nl> Signed-off-by: Ingo Molnar --- kernel/perf_counter.c | 42 ++++++++++++++++++++++++++---------------- 1 file changed, 26 insertions(+), 16 deletions(-) diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index d07b45278b4f..4471e7e2c109 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -1663,10 +1663,20 @@ struct perf_output_handle { unsigned int offset; unsigned int head; 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, - struct perf_counter *counter, unsigned int size) + struct perf_counter *counter, unsigned int size, + int nmi) { struct perf_mmap_data *data; unsigned int offset, head; @@ -1676,15 +1686,17 @@ static int perf_output_begin(struct perf_output_handle *handle, if (!data) goto out; + handle->counter = counter; + handle->nmi = nmi; + if (!data->nr_pages) - goto out; + goto fail; do { offset = head = atomic_read(&data->head); head += size; } while (atomic_cmpxchg(&data->head, offset, head) != offset); - handle->counter = counter; handle->data = data; handle->offset = offset; handle->head = head; @@ -1692,6 +1704,8 @@ static int perf_output_begin(struct perf_output_handle *handle, return 0; +fail: + __perf_output_wakeup(handle); out: rcu_read_unlock(); @@ -1733,14 +1747,10 @@ static void perf_output_copy(struct perf_output_handle *handle, #define perf_output_put(handle, 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 (nmi) - perf_pending_queue(handle->counter); - else - perf_counter_wakeup(handle->counter); - } + if (handle->wakeup) + __perf_output_wakeup(handle); rcu_read_unlock(); } @@ -1750,12 +1760,12 @@ static int perf_output_write(struct perf_counter *counter, int nmi, struct perf_output_handle handle; int ret; - ret = perf_output_begin(&handle, counter, size); + ret = perf_output_begin(&handle, counter, size, nmi); if (ret) goto out; perf_output_copy(&handle, buf, size); - perf_output_end(&handle, nmi); + perf_output_end(&handle); out: 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); - ret = perf_output_begin(&handle, counter, size); + ret = perf_output_begin(&handle, counter, size, nmi); if (ret) return; @@ -1824,7 +1834,7 @@ static void perf_output_group(struct perf_counter *counter, int nmi) perf_output_put(&handle, entry); } - perf_output_end(&handle, nmi); + perf_output_end(&handle); } 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; 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) return; @@ -1877,7 +1887,7 @@ static void perf_counter_mmap_output(struct perf_counter *counter, perf_output_put(&handle, mmap_event->event); perf_output_copy(&handle, mmap_event->file_name, mmap_event->file_size); - perf_output_end(&handle, 0); + perf_output_end(&handle); } static int perf_counter_mmap_match(struct perf_counter *counter, -- 2.34.1