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[S390] hwsampler: Set a sane default sampling rate
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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>
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Christian Borntraeger authored and Martin Schwidefsky committed Jun 22, 2011
1 parent b530ce7 commit 6815823
Showing 1 changed file with 1 addition and 1 deletion.
2 changes: 1 addition & 1 deletion arch/s390/oprofile/init.c
Original file line number Diff line number Diff line change
Expand Up @@ -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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