linux_dsm_epyc7002/arch/s390/oprofile/init.c
Heinz Graalfs 997dbb4967 oprofile, s390: Enhance OProfile to support System zs hardware sampling feature
OProfile is enhanced to export all files for controlling System z's
hardware sampling, and to invoke hwsampler exported functions to
initialize and use System z's hardware sampling.

The patch invokes hwsampler_setup() during oprofile init and exports
following hwsampler files under oprofilefs if hwsampler's setup
succeeded:

A new directory for hardware sampling based files

 /dev/oprofile/hwsampling/

The userland daemon must explicitly write to the following files
to disable (or enable) hardware based sampling

 /dev/oprofile/hwsampling/hwsampler

to modify the actual sampling rate

 /dev/oprofile/hwsampling/hw_interval

to modify the amount of sampling memory (measured in 4K pages)

 /dev/oprofile/hwsampling/hw_sdbt_blocks

The following files are read only and show
the possible minimum sampling rate

 /dev/oprofile/hwsampling/hw_min_interval

the possible maximum sampling rate

 /dev/oprofile/hwsampling/hw_max_interval

The patch splits the oprofile_timer_[init/exit] function so that it
can be also called through user context (oprofilefs) to avoid kernel
oops.

Applied with following changes:
* whitespace changes in Makefile and timer_int.c

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Maran Pakkirisamy <maranp@linux.vnet.ibm.com>
Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-02-15 11:08:50 +01:00

32 lines
722 B
C

/**
* arch/s390/oprofile/init.c
*
* S390 Version
* Copyright (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Thomas Spatzier (tspat@de.ibm.com)
*
* @remark Copyright 2002 OProfile authors
*/
#include <linux/oprofile.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/fs.h>
extern int oprofile_hwsampler_init(struct oprofile_operations* ops);
extern void oprofile_hwsampler_exit(void);
extern void s390_backtrace(struct pt_regs * const regs, unsigned int depth);
int __init oprofile_arch_init(struct oprofile_operations* ops)
{
ops->backtrace = s390_backtrace;
return oprofile_hwsampler_init(ops);
}
void oprofile_arch_exit(void)
{
oprofile_hwsampler_exit();
}