perf_counter: add more context information

Change the callchain context entries to u16, so as to gain some space.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090406094517.457320003@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 2 insertions, 4 deletions

diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 2a5d4f525567..727624db5078 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -1657,9 +1657,7 @@ void perf_counter_do_pending(void)
  * Callchain support -- arch specific
  */
 
-struct perf_callchain_entry *
-__attribute__((weak))
-perf_callchain(struct pt_regs *regs)
+__weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
 {
         return NULL;
 }
@@ -1819,7 +1817,7 @@ void perf_counter_output(struct perf_counter *counter,
                 callchain = perf_callchain(regs);
 
                 if (callchain) {
-                        callchain_size = (2 + callchain->nr) * sizeof(u64);
+                        callchain_size = (1 + callchain->nr) * sizeof(u64);
 
                         header.type |= __PERF_EVENT_CALLCHAIN;
                         header.size += callchain_size;