commit 6815823431296082fa20c2f14007e194424660b8
author Christian Borntraeger <borntraeger@de.ibm.com> Wed Jun 22 16:24:09 2011 +0200
committer Martin Schwidefsky <schwidefsky@de.ibm.com> Wed Jun 22 16:24:20 2011 +0200
tree 98bc558b3ce9c4f044a0fc5a3f99d6da86e7b895
parent b530ce7a1af5a9355be518557d86b33c6d2cf088

[S390] hwsampler: Set a sane default sampling rate

The sampling interval for the hardware sampler is specified in cycles.
(see SA23-2260-01 The Load-Program-Parameter and the CPU-Measurement
Facilities)
The current default value will therefore result in millions of samples.
This patch changes the default sampling interval to 4M, which will
result in ~1500 samples per second on a z196 reducing the overhead
of sampling.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/oprofile/init.c

diff --git a/arch/s390/oprofile/init.c b/arch/s390/oprofile/init.c
index 5e2ab03..0e358c2 100644
--- a/arch/s390/oprofile/init.c
+++ b/arch/s390/oprofile/init.c
@@ -25,7 +25,7 @@
 
 #include "hwsampler.h"
 
-#define DEFAULT_INTERVAL	4096
+#define DEFAULT_INTERVAL	4127518
 
 #define DEFAULT_SDBT_BLOCKS	1
 #define DEFAULT_SDB_BLOCKS	511