94b69c615e
It calculates IPC from the cycles and instruction counts and compares it
with the shadow stat for both global aggregation (default) and no
aggregation mode.
$ perf stat -a -A -e cycles,instructions sleep 1
Performance counter stats for 'system wide':
CPU0 39,580,880 cycles
CPU1 45,426,945 cycles
CPU2 31,151,685 cycles
CPU3 55,167,421 cycles
CPU0 17,073,564 instructions # 0.43 insn per cycle
CPU1 34,955,764 instructions # 0.77 insn per cycle
CPU2 15,688,459 instructions # 0.50 insn per cycle
CPU3 34,699,217 instructions # 0.63 insn per cycle
1.003275495 seconds time elapsed
In this example, the 'insn per cycle' should be matched to the number
for each cpu. For CPU2, 0.50 = 15,688,459 / 31,151,685 .
Committer testing:
# perf test shadow
78: perf stat metrics (shadow stat) test : Ok
#
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201127041404.390276-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
80 lines
1.5 KiB
Bash
Executable file
80 lines
1.5 KiB
Bash
Executable file
#!/bin/sh
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# perf stat metrics (shadow stat) test
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# SPDX-License-Identifier: GPL-2.0
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set -e
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# skip if system-wide mode is forbidden
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perf stat -a true > /dev/null 2>&1 || exit 2
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test_global_aggr()
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{
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local cyc
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perf stat -a --no-big-num -e cycles,instructions sleep 1 2>&1 | \
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grep -e cycles -e instructions | \
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while read num evt hash ipc rest
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do
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# skip not counted events
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if [[ $num == "<not" ]]; then
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continue
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fi
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# save cycles count
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if [[ $evt == "cycles" ]]; then
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cyc=$num
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continue
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fi
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# skip if no cycles
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if [[ -z $cyc ]]; then
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continue
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fi
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# use printf for rounding and a leading zero
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local res=`printf "%.2f" $(echo "scale=6; $num / $cyc" | bc -q)`
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if [[ $ipc != $res ]]; then
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echo "IPC is different: $res != $ipc ($num / $cyc)"
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exit 1
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fi
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done
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}
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test_no_aggr()
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{
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declare -A results
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perf stat -a -A --no-big-num -e cycles,instructions sleep 1 2>&1 | \
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grep ^CPU | \
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while read cpu num evt hash ipc rest
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do
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# skip not counted events
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if [[ $num == "<not" ]]; then
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continue
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fi
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# save cycles count
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if [[ $evt == "cycles" ]]; then
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results[$cpu]=$num
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continue
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fi
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# skip if no cycles
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local cyc=${results[$cpu]}
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if [[ -z $cyc ]]; then
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continue
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fi
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# use printf for rounding and a leading zero
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local res=`printf "%.2f" $(echo "scale=6; $num / $cyc" | bc -q)`
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if [[ $ipc != $res ]]; then
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echo "IPC is different for $cpu: $res != $ipc ($num / $cyc)"
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exit 1
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fi
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done
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}
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test_global_aggr
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test_no_aggr
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exit 0
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