Commit f849ce6b authored by Jing Zhang's avatar Jing Zhang Committed by Arnaldo Carvalho de Melo
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perf docs: Update metric usage for Alibaba's T-Head PMU driver (arm64) 



Alibaba's T-Head ali_drw PMU supports DDR bandwidth metrics. Update
its usage in the documentation.

Reviewed-by: default avatarJohn Garry <john.g.garry@oracle.com>
Signed-off-by: default avatarJing Zhang <renyu.zj@linux.alibaba.com>
Acked-by: default avatarIan Rogers <irogers@google.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Shuai Xue <xueshuai@linux.alibaba.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zhuo Song <zhuo.song@linux.alibaba.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-doc@vger.kernel.org
Link: https://lore.kernel.org/r/1690528175-2499-4-git-send-email-renyu.zj@linux.alibaba.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 3e65bd13

Documentation/admin-guide/perf/alibaba_pmu.rst

+5 −0
Original line number Diff line number Diff line
@@ -88,6 +88,11 @@ data bandwidth:: 
    -e ali_drw_27080/hif_rmw/ \

    -e ali_drw_27080/cycle/ -- sleep 10



Example usage of counting all memory read/write bandwidth by metric::



  perf stat -M ddr_read_bandwidth.all -- sleep 10

  perf stat -M ddr_write_bandwidth.all -- sleep 10



The average DRAM bandwidth can be calculated as follows:



- Read Bandwidth =  perf_hif_rd * DDRC_WIDTH * DDRC_Freq / DDRC_Cycle