This is a note to let you know that I've just added the patch titled
perf ftrace latency: Fix unit on histogram first entry when using --use-nsec
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
perf-ftrace-latency-fix-unit-on-histogram-first-entr.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d2a515c02837d3f30029b09eef1dd3273e21ea60
Author: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Date: Tue Oct 29 16:29:02 2024 -0300
perf ftrace latency: Fix unit on histogram first entry when using --use-nsec
[ Upstream commit 064d569e20e82c065b1dec9d20c29c7087bb1a00 ]
The use_nsec arg wasn't being taken into account when printing the first
histogram entry, fix it:
root@number:~# perf ftrace latency --use-nsec -T switch_mm_irqs_off -a sleep 2
# DURATION | COUNT | GRAPH |
0 - 1 us | 0 | |
1 - 2 ns | 0 | |
2 - 4 ns | 0 | |
4 - 8 ns | 0 | |
8 - 16 ns | 0 | |
16 - 32 ns | 0 | |
32 - 64 ns | 125 | |
64 - 128 ns | 335 | |
128 - 256 ns | 2155 | #### |
256 - 512 ns | 9996 | ################### |
512 - 1024 ns | 4958 | ######### |
1 - 2 us | 4636 | ######### |
2 - 4 us | 1053 | ## |
4 - 8 us | 15 | |
8 - 16 us | 1 | |
16 - 32 us | 0 | |
32 - 64 us | 0 | |
64 - 128 us | 0 | |
128 - 256 us | 0 | |
256 - 512 us | 0 | |
512 - 1024 us | 0 | |
1 - ... ms | 0 | |
root@number:~#
After:
root@number:~# perf ftrace latency --use-nsec -T switch_mm_irqs_off -a sleep 2
# DURATION | COUNT | GRAPH |
0 - 1 ns | 0 | |
1 - 2 ns | 0 | |
2 - 4 ns | 0 | |
4 - 8 ns | 0 | |
8 - 16 ns | 0 | |
16 - 32 ns | 0 | |
32 - 64 ns | 19 | |
64 - 128 ns | 94 | |
128 - 256 ns | 2191 | #### |
256 - 512 ns | 9719 | #################### |
512 - 1024 ns | 5330 | ########### |
1 - 2 us | 4104 | ######## |
2 - 4 us | 807 | # |
4 - 8 us | 9 | |
8 - 16 us | 0 | |
16 - 32 us | 0 | |
32 - 64 us | 0 | |
64 - 128 us | 0 | |
128 - 256 us | 0 | |
256 - 512 us | 0 | |
512 - 1024 us | 0 | |
1 - ... ms | 0 | |
root@number:~#
Fixes: 84005bb6148618cc ("perf ftrace latency: Add -n/--use-nsec option")
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Gabriele Monaco <gmonaco@xxxxxxxxxx>
Link: https://lore.kernel.org/r/ZyE3frB-hMXHCnMO@x1
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 1d40f9bcb63bc..86597f6119003 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -769,7 +769,7 @@ static void display_histogram(int buckets[], bool use_nsec)
bar_len = buckets[0] * bar_total / total;
printf(" %4d - %-4d %s | %10d | %.*s%*s |\n",
- 0, 1, "us", buckets[0], bar_len, bar, bar_total - bar_len, "");
+ 0, 1, use_nsec ? "ns" : "us", buckets[0], bar_len, bar, bar_total - bar_len, "");
for (i = 1; i < NUM_BUCKET - 1; i++) {
int start = (1 << (i - 1));
