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authorChristian Borntraeger <borntraeger@de.ibm.com>2011-06-22 16:24:09 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2011-06-22 16:24:20 +0200
commit6815823431296082fa20c2f14007e194424660b8 (patch)
tree98bc558b3ce9c4f044a0fc5a3f99d6da86e7b895
parentb530ce7a1af5a9355be518557d86b33c6d2cf088 (diff)
downloadop-kernel-dev-6815823431296082fa20c2f14007e194424660b8.zip
op-kernel-dev-6815823431296082fa20c2f14007e194424660b8.tar.gz
[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>
-rw-r--r--arch/s390/oprofile/init.c2
1 files changed, 1 insertions, 1 deletions
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 @@ extern void s390_backtrace(struct pt_regs * const regs, unsigned int depth);
#include "hwsampler.h"
-#define DEFAULT_INTERVAL 4096
+#define DEFAULT_INTERVAL 4127518
#define DEFAULT_SDBT_BLOCKS 1
#define DEFAULT_SDB_BLOCKS 511
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