• Yicong Yang's avatar
    drivers/perf: hisi_pcie: Fix incorrect counting under metric mode · b6693ad6
    Yicong Yang authored
    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: 8404b0fb ("drivers/perf: hisi: Add driver for HiSilicon PCIe PMU")
    Signed-off-by: default avatarYicong Yang <yangyicong@hisilicon.com>
    Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
    Link: https://lore.kernel.org/r/20240223103359.18669-4-yangyicong@huawei.comSigned-off-by: default avatarWill Deacon <will@kernel.org>
    b6693ad6
hisi_pcie_pmu.c 26.3 KB