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| H A D | hisi_pcie_pmu.c | b6693ad6 Fri Feb 23 10:33:54 GMT 2024 Yicong Yang <yangyicong@hisilicon.com> drivers/perf: hisi_pcie: Fix incorrect counting under metric mode
The metric counting shows incorrect results if the events in the
metric group using the same event but different filter options.
This is because we only judge the event code to decide whether
the event in the metric group should share the same hardware
counter, but ignore the settings of the filter.
For example, on a platform of 2 ports 0x1 and 0x2 but only port
0x1 has a downstream PCIe NVME device. The metric counting
shows both ports have the same counts because we misassign these
two events to one same hardware counter:
[root@localhost perf-iostat]# ./perf stat -e '{hisi_pcie0_core1/event=0x0104,port=0x2/,hisi_pcie0_core1/event=0x0104,port=0x1/}'
Performance counter stats for 'system wide':
7907484924 hisi_pcie0_core1/event=0x0104,port=0x2/
7907484924 hisi_pcie0_core1/event=0x0104,port=0x1/
10.153863691 seconds time elapsed
Fix this by using the whole config rather than the event only
to judge whether two events are the same and should share the
same hardware counter. With this patch, the metric counting in
the above case tends to be corrected:
[root@localhost perf-iostat]# ./perf stat -e '{hisi_pcie0_core1/event=0x0104,port=0x2/,hisi_pcie0_core1/event=0x0104,port=0x1/}'
Performance counter stats for 'system wide':
0 hisi_pcie0_core1/event=0x0104,port=0x2/
8123122077 hisi_pcie0_core1/event=0x0104,port=0x1/
10.152875631 seconds time elapsed
Fixes: 8404b0fbc7fb ("drivers/perf: hisi: Add driver for HiSilicon PCIe PMU")
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240223103359.18669-4-yangyicong@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
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