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authorThomas Gleixner <tglx@linutronix.de>2008-12-04 20:12:29 +0100
committerIngo Molnar <mingo@elte.hu>2008-12-08 15:47:03 +0100
commit0793a61d4df8daeac6492dbf8d2f3e5713caae5e (patch)
treecc9603eb8daffeb7ace521c42a6a44db164ac551 /drivers/char/sysrq.c
parentb5aa97e83bcc31a96374d18f5452d53909a16c90 (diff)
performance counters: core code
Implement the core kernel bits of Performance Counters subsystem. The Linux Performance Counter subsystem provides an abstraction of performance counter hardware capabilities. It provides per task and per CPU counters, and it provides event capabilities on top of those. Performance counters are accessed via special file descriptors. There's one file descriptor per virtual counter used. The special file descriptor is opened via the perf_counter_open() system call: int perf_counter_open(u32 hw_event_type, u32 hw_event_period, u32 record_type, pid_t pid, int cpu); The syscall returns the new fd. The fd can be used via the normal VFS system calls: read() can be used to read the counter, fcntl() can be used to set the blocking mode, etc. Multiple counters can be kept open at a time, and the counters can be poll()ed. See more details in Documentation/perf-counters.txt. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'drivers/char/sysrq.c')
-rw-r--r--drivers/char/sysrq.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/char/sysrq.c b/drivers/char/sysrq.c
index ce0d9da52a8a..52146c2a8d97 100644
--- a/drivers/char/sysrq.c
+++ b/drivers/char/sysrq.c
@@ -25,6 +25,7 @@
#include <linux/kbd_kern.h>
#include <linux/proc_fs.h>
#include <linux/quotaops.h>
+#include <linux/perf_counter.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/suspend.h>
@@ -244,6 +245,7 @@ static void sysrq_handle_showregs(int key, struct tty_struct *tty)
struct pt_regs *regs = get_irq_regs();
if (regs)
show_regs(regs);
+ perf_counter_print_debug();
}
static struct sysrq_key_op sysrq_showregs_op = {
.handler = sysrq_handle_showregs,