perf: Remove more code from the fastpath

Sanity checks cost instructions.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100521090710.852926930@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 4 insertions, 16 deletions

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 953ce46d7b2f..d25c864cadbf 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -2967,20 +2967,11 @@ again:
         preempt_enable();
 }
 
-void perf_output_copy(struct perf_output_handle *handle,
+__always_inline void perf_output_copy(struct perf_output_handle *handle,
                       const void *buf, unsigned int len)
 {
-        handle->offset += len;
-
-        /*
-         * Check we didn't copy past our reservation window, taking the
-         * possible unsigned int wrap into account.
-         */
-        if (WARN_ON_ONCE(((long)(handle->head - handle->offset)) < 0))
-                return;
-
         do {
-                unsigned long size = min(handle->size, len);
+                unsigned long size = min_t(unsigned long, handle->size, len);
 
                 memcpy(handle->addr, buf, size);
 
@@ -3055,15 +3046,12 @@ int perf_output_begin(struct perf_output_handle *handle,
                         goto fail;
         } while (local_cmpxchg(&data->head, offset, head) != offset);
 
-        handle->offset  = offset;
-        handle->head    = head;
-
         if (head - local_read(&data->wakeup) > data->watermark)
                 local_add(data->watermark, &data->wakeup);
 
-        handle->page = handle->offset >> (PAGE_SHIFT + page_order(data));
+        handle->page = offset >> (PAGE_SHIFT + page_order(data));
         handle->page &= data->nr_pages - 1;
-        handle->size = handle->offset & ((PAGE_SIZE << page_order(data)) - 1);
+        handle->size = offset & ((PAGE_SIZE << page_order(data)) - 1);
         handle->addr = data->data_pages[handle->page];
         handle->addr += handle->size;
         handle->size = (PAGE_SIZE << page_order(data)) - handle->size;