Messages in this thread Patch in this message | | | From | Jin Yao <> | Subject | [PATCH] perf stat: Fix wrong skipping for per-die aggregation | Date | Wed, 16 Dec 2020 15:01:46 +0800 |
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Uncore becomes die-scope on Xeon Cascade Lake-AP and perf has supported --per-die aggregation yet.
One issue is found in check_per_pkg() for uncore events running on AP system. On cascade Lake-AP, we have:
S0-D0 S0-D1 S1-D0 S1-D1
But in check_per_pkg(), S0-D1 and S1-D1 are skipped because the mask bits for S0 and S1 have been set for S0-D0 and S1-D0. It doesn't check die_id. So the counting for S0-D1 and S1-D1 are set to zero. That's not correct.
root@lkp-csl-2ap4 ~# ./perf stat -a -I 1000 -e llc_misses.mem_read --per-die -- sleep 5 1.001460963 S0-D0 1 1317376 Bytes llc_misses.mem_read 1.001460963 S0-D1 1 998016 Bytes llc_misses.mem_read 1.001460963 S1-D0 1 970496 Bytes llc_misses.mem_read 1.001460963 S1-D1 1 1291264 Bytes llc_misses.mem_read 2.003488021 S0-D0 1 1082048 Bytes llc_misses.mem_read 2.003488021 S0-D1 1 1919040 Bytes llc_misses.mem_read 2.003488021 S1-D0 1 890752 Bytes llc_misses.mem_read 2.003488021 S1-D1 1 2380800 Bytes llc_misses.mem_read 3.005613270 S0-D0 1 1126080 Bytes llc_misses.mem_read 3.005613270 S0-D1 1 2898176 Bytes llc_misses.mem_read 3.005613270 S1-D0 1 870912 Bytes llc_misses.mem_read 3.005613270 S1-D1 1 3388608 Bytes llc_misses.mem_read 4.007627598 S0-D0 1 1124608 Bytes llc_misses.mem_read 4.007627598 S0-D1 1 3884416 Bytes llc_misses.mem_read 4.007627598 S1-D0 1 921088 Bytes llc_misses.mem_read 4.007627598 S1-D1 1 4451840 Bytes llc_misses.mem_read 5.001479927 S0-D0 1 963328 Bytes llc_misses.mem_read 5.001479927 S0-D1 1 4831936 Bytes llc_misses.mem_read 5.001479927 S1-D0 1 895104 Bytes llc_misses.mem_read 5.001479927 S1-D1 1 5496640 Bytes llc_misses.mem_read
From above output, we can see S0-D1 and S1-D1 don't report the interval values, they are continued to grow. That's because check_per_pkg() wrongly decides to use zero counts for S0-D1 and S1-D1.
So in check_per_pkg(), we should use a pair of die_id + socket_id to decide if this cpu counts needs to skip. Only considering socket_id is not enough.
Now with this patch,
root@lkp-csl-2ap4 ~# ./perf stat -a -I 1000 -e llc_misses.mem_read --per-die -- sleep 5 1.001622560 S0-D0 1 1210176 Bytes llc_misses.mem_read 1.001622560 S0-D1 1 950208 Bytes llc_misses.mem_read 1.001622560 S1-D0 1 968704 Bytes llc_misses.mem_read 1.001622560 S1-D1 1 1113280 Bytes llc_misses.mem_read 2.004399430 S0-D0 1 1258560 Bytes llc_misses.mem_read 2.004399430 S0-D1 1 1011008 Bytes llc_misses.mem_read 2.004399430 S1-D0 1 1036544 Bytes llc_misses.mem_read 2.004399430 S1-D1 1 1237376 Bytes llc_misses.mem_read 3.006535657 S0-D0 1 1036608 Bytes llc_misses.mem_read 3.006535657 S0-D1 1 906560 Bytes llc_misses.mem_read 3.006535657 S1-D0 1 994112 Bytes llc_misses.mem_read 3.006535657 S1-D1 1 1025472 Bytes llc_misses.mem_read 4.008934402 S0-D0 1 1005120 Bytes llc_misses.mem_read 4.008934402 S0-D1 1 882368 Bytes llc_misses.mem_read 4.008934402 S1-D0 1 961408 Bytes llc_misses.mem_read 4.008934402 S1-D1 1 988352 Bytes llc_misses.mem_read 5.001605406 S0-D0 1 1930240 Bytes llc_misses.mem_read 5.001605406 S0-D1 1 1134272 Bytes llc_misses.mem_read 5.001605406 S1-D0 1 1531136 Bytes llc_misses.mem_read 5.001605406 S1-D1 1 2230848 Bytes llc_misses.mem_read
On no-die system, die_id is 0, this patch keeps original behavior unchanged.
Reported-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Jin Yao <yao.jin@linux.intel.com> --- tools/perf/util/cpumap.h | 2 ++ tools/perf/util/stat.c | 21 +++++++++++++++++---- 2 files changed, 19 insertions(+), 4 deletions(-)
diff --git a/tools/perf/util/cpumap.h b/tools/perf/util/cpumap.h index 3a442f021468..58604c047121 100644 --- a/tools/perf/util/cpumap.h +++ b/tools/perf/util/cpumap.h @@ -7,6 +7,8 @@ #include <internal/cpumap.h> #include <perf/cpumap.h> +#define CPU_MAP_MAX_DIE 256 + struct perf_record_cpu_map_data; struct perf_cpu_map *perf_cpu_map__empty_new(int nr); diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c index 1e125e39ff84..b3fc6e261fe0 100644 --- a/tools/perf/util/stat.c +++ b/tools/perf/util/stat.c @@ -282,9 +282,9 @@ static void zero_per_pkg(struct evsel *counter) static int check_per_pkg(struct evsel *counter, struct perf_counts_values *vals, int cpu, bool *skip) { - unsigned long *mask = counter->per_pkg_mask; + unsigned long *mask = counter->per_pkg_mask, *l; struct perf_cpu_map *cpus = evsel__cpus(counter); - int s; + int s, d; *skip = false; @@ -295,7 +295,7 @@ static int check_per_pkg(struct evsel *counter, return 0; if (!mask) { - mask = zalloc(cpu__max_cpu()); + mask = zalloc(cpu__max_cpu() * CPU_MAP_MAX_DIE); if (!mask) return -ENOMEM; @@ -317,7 +317,20 @@ static int check_per_pkg(struct evsel *counter, if (s < 0) return -1; - *skip = test_and_set_bit(s, mask) == 1; + d = cpu_map__get_die(cpus, cpu, NULL); + if (d < 0) + return -1; + + /* + * On multi-die system, die_id < 256. We use a pair + * of socket + die to identify the used bit. + * On no-die system, die_id is 0, l = &mask[0]. It doesn't + * change original "test_and_set_bit(s, mask)" behavior. + */ + d &= 0xff; + l = &mask[d]; + + *skip = test_and_set_bit(s, l) == 1; return 0; } -- 2.17.1
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