diff options
Diffstat (limited to 'Documentation/trace')
| -rw-r--r-- | Documentation/trace/tracepoint-analysis.txt | 40 |
1 files changed, 20 insertions, 20 deletions
diff --git a/Documentation/trace/tracepoint-analysis.txt b/Documentation/trace/tracepoint-analysis.txt index 87bee3c129ba..058cc6c9dc56 100644 --- a/Documentation/trace/tracepoint-analysis.txt +++ b/Documentation/trace/tracepoint-analysis.txt @@ -93,14 +93,14 @@ By specifying the -a switch and analysing sleep, the system-wide events for a duration of time can be examined. $ perf stat -a \ - -e kmem:mm_page_alloc -e kmem:mm_page_free_direct \ - -e kmem:mm_pagevec_free \ + -e kmem:mm_page_alloc -e kmem:mm_page_free \ + -e kmem:mm_page_free_batched \ sleep 10 Performance counter stats for 'sleep 10': 9630 kmem:mm_page_alloc - 2143 kmem:mm_page_free_direct - 7424 kmem:mm_pagevec_free + 2143 kmem:mm_page_free + 7424 kmem:mm_page_free_batched 10.002577764 seconds time elapsed @@ -119,15 +119,15 @@ basis using set_ftrace_pid. Events can be activated and tracked for the duration of a process on a local basis using PCL such as follows. - $ perf stat -e kmem:mm_page_alloc -e kmem:mm_page_free_direct \ - -e kmem:mm_pagevec_free ./hackbench 10 + $ perf stat -e kmem:mm_page_alloc -e kmem:mm_page_free \ + -e kmem:mm_page_free_batched ./hackbench 10 Time: 0.909 Performance counter stats for './hackbench 10': 17803 kmem:mm_page_alloc - 12398 kmem:mm_page_free_direct - 4827 kmem:mm_pagevec_free + 12398 kmem:mm_page_free + 4827 kmem:mm_page_free_batched 0.973913387 seconds time elapsed @@ -146,8 +146,8 @@ to know what the standard deviation is. By and large, this is left to the performance analyst to do it by hand. In the event that the discrete event occurrences are useful to the performance analyst, then perf can be used. - $ perf stat --repeat 5 -e kmem:mm_page_alloc -e kmem:mm_page_free_direct - -e kmem:mm_pagevec_free ./hackbench 10 + $ perf stat --repeat 5 -e kmem:mm_page_alloc -e kmem:mm_page_free + -e kmem:mm_page_free_batched ./hackbench 10 Time: 0.890 Time: 0.895 Time: 0.915 @@ -157,8 +157,8 @@ occurrences are useful to the performance analyst, then perf can be used. Performance counter stats for './hackbench 10' (5 runs): 16630 kmem:mm_page_alloc ( +- 3.542% ) - 11486 kmem:mm_page_free_direct ( +- 4.771% ) - 4730 kmem:mm_pagevec_free ( +- 2.325% ) + 11486 kmem:mm_page_free ( +- 4.771% ) + 4730 kmem:mm_page_free_batched ( +- 2.325% ) 0.982653002 seconds time elapsed ( +- 1.448% ) @@ -168,15 +168,15 @@ aggregation of discrete events, then a script would need to be developed. Using --repeat, it is also possible to view how events are fluctuating over time on a system-wide basis using -a and sleep. - $ perf stat -e kmem:mm_page_alloc -e kmem:mm_page_free_direct \ - -e kmem:mm_pagevec_free \ + $ perf stat -e kmem:mm_page_alloc -e kmem:mm_page_free \ + -e kmem:mm_page_free_batched \ -a --repeat 10 \ sleep 1 Performance counter stats for 'sleep 1' (10 runs): 1066 kmem:mm_page_alloc ( +- 26.148% ) - 182 kmem:mm_page_free_direct ( +- 5.464% ) - 890 kmem:mm_pagevec_free ( +- 30.079% ) + 182 kmem:mm_page_free ( +- 5.464% ) + 890 kmem:mm_page_free_batched ( +- 30.079% ) 1.002251757 seconds time elapsed ( +- 0.005% ) @@ -220,8 +220,8 @@ were generating events within the kernel. To begin this sort of analysis, the data must be recorded. At the time of writing, this required root: $ perf record -c 1 \ - -e kmem:mm_page_alloc -e kmem:mm_page_free_direct \ - -e kmem:mm_pagevec_free \ + -e kmem:mm_page_alloc -e kmem:mm_page_free \ + -e kmem:mm_page_free_batched \ ./hackbench 10 Time: 0.894 [ perf record: Captured and wrote 0.733 MB perf.data (~32010 samples) ] @@ -260,8 +260,8 @@ noticed that X was generating an insane amount of page allocations so let's look at it: $ perf record -c 1 -f \ - -e kmem:mm_page_alloc -e kmem:mm_page_free_direct \ - -e kmem:mm_pagevec_free \ + -e kmem:mm_page_alloc -e kmem:mm_page_free \ + -e kmem:mm_page_free_batched \ -p `pidof X` This was interrupted after a few seconds and |