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Date: Thu, 24 Dec 2020 21:31:13 +0800
From: "Jin, Yao" <yao.jin@...ux.intel.com>
To: Arnaldo Carvalho de Melo <acme@...nel.org>
Cc: James Clark <james.clark@....com>,
John Garry <john.garry@...wei.com>,
Jiri Olsa <jolsa@...nel.org>,
Peter Zijlstra <peterz@...radead.org>,
Ingo Molnar <mingo@...nel.org>,
alexander.shishkin@...ux.intel.com, Linux-kernel@...r.kernel.org,
ak@...ux.intel.com, kan.liang@...el.com, yao.jin@...el.com,
ying.huang@...el.com
Subject: Re: [PATCH v2] perf stat: Fix wrong skipping for per-die aggregation
Hi Arnaldo,
On 12/24/2020 9:26 PM, Arnaldo Carvalho de Melo wrote:
> Em Thu, Dec 24, 2020 at 08:54:04PM +0800, Jin Yao escreveu:
>> 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
>
> So, I applied a series that refactors the perf stat aggregation code and
> your patch albeit applying cleanly, doesn't compile:
>
> CC /tmp/build/perf/util/topdown.o
> util/stat.c: In function ‘check_per_pkg’:
> util/stat.c:348:6: error: incompatible types when assigning to type ‘int’ from type ‘struct aggr_cpu_id’
> 348 | d = cpu_map__get_die(cpus, cpu, NULL);
> | ^~~~~~~~~~~~~~~~
> make[4]: *** [/home/acme/git/perf/tools/build/Makefile.build:97: /tmp/build/perf/util/stat.o] Error 1
> make[4]: *** Waiting for unfinished jobs....
>
>
> I'm still testing this to push publicly to my perf/core branch, but I'll
> push now to tmp.perf/core and you can go from there, ok?
>
That's OK for me.
> This is what you should find there, just pushed:
>
> 8d4852b468c38168 (HEAD -> perf/core, five/perf/core) perf stat aggregation: Add separate thread member
> b993381779da406c perf stat aggregation: Add separate core member
> ba2ee166d92b2010 perf stat aggregation: Add separate die member
> 1a270cb6b3cc1866 perf stat aggregation: Add separate socket member
> fcd83a35dd93b89d perf stat aggregation: Add separate node member
> ff5232956e074994 perf stat aggregation: Start using cpu_aggr_id in map
> d526e1a033e03ec4 perf cpumap: Drop in cpu_aggr_map struct
> cea6575fdccfc062 perf cpumap: Add new map type for aggregation
> 2760f5a14fe7aa46 perf stat: Replace aggregation ID with a struct
> fa265e59b81a09fa perf cpumap: Add new struct for cpu aggregation
> 91585846f105ef2e perf cpumap: Use existing allocator to avoid using malloc
> 23331eeb731a503a perf tests: Improve topology test to check all aggregation types
> b27d20ab1c6a1a77 perf tools: Update s390's syscall.tbl copy from the kernel sources
> c5ef52944a2d8001 perf tools: Update powerpc's syscall.tbl copy from the kernel sources
> 22ffc3f5598d2a51 perf s390: Move syscall.tbl check into check-headers.sh
> [acme@...co perf]$
>
> - Arnaldo
>
BTW, do you think if this patchset also needs to replace the "struct perf_cpu_map" in "struct
perf_evsel"? Otherwise the evsel->cpus will be inconsistent, right?
struct perf_evsel {
...
struct perf_cpu_map *cpus;
struct perf_cpu_map *own_cpus;
...
};
Thanks
Jin Yao
>> 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@...-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 hashmap(socket,die) to decide if
>> the cpu counts needs to skip. Only considering socket is not enough.
>>
>> Now with this patch,
>>
>> root@...-csl-2ap4 ~# ./perf stat -a -I 1000 -e llc_misses.mem_read --per-die -- sleep 5
>> 1.001617187 S0-D0 1 952768 Bytes llc_misses.mem_read
>> 1.001617187 S0-D1 1 849152 Bytes llc_misses.mem_read
>> 1.001617187 S1-D0 1 854912 Bytes llc_misses.mem_read
>> 1.001617187 S1-D1 1 948672 Bytes llc_misses.mem_read
>> 2.004138021 S0-D0 1 1200256 Bytes llc_misses.mem_read
>> 2.004138021 S0-D1 1 899840 Bytes llc_misses.mem_read
>> 2.004138021 S1-D0 1 898752 Bytes llc_misses.mem_read
>> 2.004138021 S1-D1 1 1039424 Bytes llc_misses.mem_read
>> 3.006463971 S0-D0 1 1029056 Bytes llc_misses.mem_read
>> 3.006463971 S0-D1 1 894336 Bytes llc_misses.mem_read
>> 3.006463971 S1-D0 1 905088 Bytes llc_misses.mem_read
>> 3.006463971 S1-D1 1 1042880 Bytes llc_misses.mem_read
>> 4.008831441 S0-D0 1 920576 Bytes llc_misses.mem_read
>> 4.008831441 S0-D1 1 877248 Bytes llc_misses.mem_read
>> 4.008831441 S1-D0 1 883968 Bytes llc_misses.mem_read
>> 4.008831441 S1-D1 1 967168 Bytes llc_misses.mem_read
>> 5.001441349 S0-D0 1 864704 Bytes llc_misses.mem_read
>> 5.001441349 S0-D1 1 827456 Bytes llc_misses.mem_read
>> 5.001441349 S1-D0 1 829632 Bytes llc_misses.mem_read
>> 5.001441349 S1-D1 1 925760 Bytes llc_misses.mem_read
>>
>> On no-die system, die_id is 0, actually it's hashmap(socket,0), original behavior
>> is not changed.
>>
>> Reported-by: Huang Ying <ying.huang@...el.com>
>> Signed-off-by: Jin Yao <yao.jin@...ux.intel.com>
>> ---
>> tools/perf/util/evsel.c | 4 ++-
>> tools/perf/util/evsel.h | 3 +-
>> tools/perf/util/stat.c | 61 +++++++++++++++++++++++++++++++++++++----
>> 3 files changed, 60 insertions(+), 8 deletions(-)
>>
>> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
>> index c26ea82220bd..9715ed9b03f6 100644
>> --- a/tools/perf/util/evsel.c
>> +++ b/tools/perf/util/evsel.c
>> @@ -45,6 +45,7 @@
>> #include "string2.h"
>> #include "memswap.h"
>> #include "util.h"
>> +#include "hashmap.h"
>> #include "../perf-sys.h"
>> #include "util/parse-branch-options.h"
>> #include <internal/xyarray.h>
>> @@ -1377,7 +1378,8 @@ void evsel__exit(struct evsel *evsel)
>> zfree(&evsel->group_name);
>> zfree(&evsel->name);
>> zfree(&evsel->pmu_name);
>> - zfree(&evsel->per_pkg_mask);
>> + hashmap__free(evsel->per_pkg_mask);
>> + evsel->per_pkg_mask = NULL;
>> zfree(&evsel->metric_events);
>> perf_evsel__object.fini(evsel);
>> }
>> diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
>> index cd1d8dd43199..951628943fd0 100644
>> --- a/tools/perf/util/evsel.h
>> +++ b/tools/perf/util/evsel.h
>> @@ -17,6 +17,7 @@ struct cgroup;
>> struct perf_counts;
>> struct perf_stat_evsel;
>> union perf_event;
>> +struct hashmap;
>>
>> typedef int (evsel__sb_cb_t)(union perf_event *event, void *data);
>>
>> @@ -110,7 +111,7 @@ struct evsel {
>> bool merged_stat;
>> bool reset_group;
>> bool errored;
>> - unsigned long *per_pkg_mask;
>> + struct hashmap *per_pkg_mask;
>> struct evsel *leader;
>> struct list_head config_terms;
>> int err;
>> diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
>> index 1e125e39ff84..15db4bda1266 100644
>> --- a/tools/perf/util/stat.c
>> +++ b/tools/perf/util/stat.c
>> @@ -13,6 +13,7 @@
>> #include "evlist.h"
>> #include "evsel.h"
>> #include "thread_map.h"
>> +#include "hashmap.h"
>> #include <linux/zalloc.h>
>>
>> void update_stats(struct stats *stats, u64 val)
>> @@ -275,16 +276,39 @@ void evlist__save_aggr_prev_raw_counts(struct evlist *evlist)
>>
>> static void zero_per_pkg(struct evsel *counter)
>> {
>> - if (counter->per_pkg_mask)
>> - memset(counter->per_pkg_mask, 0, cpu__max_cpu());
>> + struct hashmap_entry *entry;
>> + size_t bkt;
>> +
>> + if (counter->per_pkg_mask) {
>> + hashmap__for_each_entry(counter->per_pkg_mask, entry, bkt) {
>> + bool *used = (bool *)entry->value;
>> +
>> + *used = false;
>> + }
>> + }
>> +}
>> +
>> +static size_t id_hash(const void *key, void *ctx __maybe_unused)
>> +{
>> + int socket = (int64_t)key >> 32;
>> +
>> + return socket;
>> +}
>> +
>> +static bool id_equal(const void *key1, const void *key2,
>> + void *ctx __maybe_unused)
>> +{
>> + return (int64_t)key1 == (int64_t)key2;
>> }
>>
>> static int check_per_pkg(struct evsel *counter,
>> struct perf_counts_values *vals, int cpu, bool *skip)
>> {
>> - unsigned long *mask = counter->per_pkg_mask;
>> + struct hashmap *mask = counter->per_pkg_mask;
>> struct perf_cpu_map *cpus = evsel__cpus(counter);
>> - int s;
>> + int s, d, ret;
>> + uint64_t key;
>> + bool *used;
>>
>> *skip = false;
>>
>> @@ -295,7 +319,7 @@ static int check_per_pkg(struct evsel *counter,
>> return 0;
>>
>> if (!mask) {
>> - mask = zalloc(cpu__max_cpu());
>> + mask = hashmap__new(id_hash, id_equal, NULL);
>> if (!mask)
>> return -ENOMEM;
>>
>> @@ -317,7 +341,32 @@ static int check_per_pkg(struct evsel *counter,
>> if (s < 0)
>> return -1;
>>
>> - *skip = test_and_set_bit(s, mask) == 1;
>> + /*
>> + * On multi-die system, 0 < die_id < 256. On no-die system, die_id = 0.
>> + * We use hashmap(socket, die) to check the used socket+die pair.
>> + */
>> + d = cpu_map__get_die(cpus, cpu, NULL);
>> + if (d < 0)
>> + return -1;
>> +
>> + key = (uint64_t)s << 32 | (d & 0xff);
>> + if (hashmap__find(mask, (void *)key, (void **)&used)) {
>> + if (*used)
>> + *skip = true;
>> + *used = true;
>> + } else {
>> + used = zalloc(sizeof(*used));
>> + if (!used)
>> + return -1;
>> +
>> + *used = true;
>> + ret = hashmap__add(mask, (void *)key, used);
>> + if (ret) {
>> + free(used);
>> + return -1;
>> + }
>> + }
>> +
>> return 0;
>> }
>>
>> --
>> 2.17.1
>>
>
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