Public bug reported:
This upstream patch from v6.19 resolves an issue (injected with a v6.16
commit) when running the perf command to measure duration time.
When running in interval mode every third count of a time event isn't
showing properly:
```
$ perf stat -e duration_time -a -I 1000
1.001082862 1,002,290,425 duration_time
2.004264262 1,003,183,516 duration_time
3.007381401 <not counted> duration_time
4.011160141 1,003,705,631 duration_time
5.014515385 1,003,290,110 duration_time
6.018539680 <not counted> duration_time
7.022065321 1,003,591,720 duration_time
```
Patch:
https://github.com/torvalds/linux/commit/bdf96c4ecd69523d97c98e47284caddde20b1df7
LKML: https://lore.kernel.org/all/[email protected]/
Backport the patch to linux-nvidia-6.17.
Verified by running the perf command with the fix:
```
nvidia@GB200:~/mochs/perf_backport_test/NV-Kernels/tools/perf$ ./perf stat -e
duration_time -I 1000
./perf stat -e duration_time -I 1000
# time counts unit events
1.001015119 1008476614 duration_time
2.004164516 1003143445 duration_time
3.008193019 1004027831 duration_time
4.012104305 1003915414 duration_time
5.016211177 1004100920 duration_time
6.019747039 1003552054 duration_time
6.674403830 654646104 duration_time
```
** Affects: linux-nvidia-6.17 (Ubuntu)
Importance: Undecided
Status: New
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https://bugs.launchpad.net/bugs/2158038
Title:
Backport perf tool_pmu: Use old_count when computing count values for
time events
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