lkml.org 
[lkml]   [2009]   [Apr]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH 08/15] perf_counter: PERF_RECORD_TIME
By popular request, provide means to log a timestamp along with the
counter overflow event.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
include/linux/perf_counter.h | 2 ++
kernel/perf_counter.c | 14 ++++++++++++++
2 files changed, 16 insertions(+)

Index: linux-2.6/include/linux/perf_counter.h
===================================================================
--- linux-2.6.orig/include/linux/perf_counter.h
+++ linux-2.6/include/linux/perf_counter.h
@@ -102,6 +102,7 @@ enum perf_counter_record_format {
PERF_RECORD_TID = 1U << 1,
PERF_RECORD_GROUP = 1U << 2,
PERF_RECORD_CALLCHAIN = 1U << 3,
+ PERF_RECORD_TIME = 1U << 4,
};

/*
@@ -221,6 +222,7 @@ enum perf_event_type {
__PERF_EVENT_TID = PERF_RECORD_TID,
__PERF_EVENT_GROUP = PERF_RECORD_GROUP,
__PERF_EVENT_CALLCHAIN = PERF_RECORD_CALLCHAIN,
+ __PERF_EVENT_TIME = PERF_RECORD_TIME,
};

#ifdef __KERNEL__
Index: linux-2.6/kernel/perf_counter.c
===================================================================
--- linux-2.6.orig/kernel/perf_counter.c
+++ linux-2.6/kernel/perf_counter.c
@@ -1823,6 +1823,7 @@ static void perf_counter_output(struct p
} group_entry;
struct perf_callchain_entry *callchain = NULL;
int callchain_size = 0;
+ u64 time;

header.type = PERF_EVENT_COUNTER_OVERFLOW;
header.size = sizeof(header);
@@ -1859,6 +1860,16 @@ static void perf_counter_output(struct p
}
}

+ if (record_type & PERF_RECORD_TIME) {
+ /*
+ * Maybe do better on x86 and provide cpu_clock_nmi()
+ */
+ time = sched_clock();
+
+ header.type |= __PERF_EVENT_TIME;
+ header.size += sizeof(u64);
+ }
+
ret = perf_output_begin(&handle, counter, header.size, nmi);
if (ret)
return;
@@ -1892,6 +1903,9 @@ static void perf_counter_output(struct p
if (callchain)
perf_output_copy(&handle, callchain, callchain_size);

+ if (record_type & PERF_RECORD_TIME)
+ perf_output_put(&handle, time);
+
perf_output_end(&handle);
}

--



\
 
 \ /
  Last update: 2009-04-06 11:49    [W:0.181 / U:0.012 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site