On Fri, May 22, 2020 at 7:59 AM Ian Rogers <irogers@xxxxxxxxxx> wrote: > > > > On Fri, May 22, 2020, 7:49 AM Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> wrote: >> >> Em Fri, May 22, 2020 at 12:13:11PM +0200, Jiri Olsa escreveu: >> > On Thu, May 21, 2020 at 02:22:35PM -0300, Arnaldo Carvalho de Melo wrote: >> > > Em Thu, May 21, 2020 at 01:43:25PM +0200, Jiri Olsa escreveu: >> > > > On Wed, May 20, 2020 at 11:20:04AM -0700, Ian Rogers wrote: >> > > > >> > > > SNIP >> > > > >> > > > > There are 5 out of 12 metric groups where no events are shared, such >> > > > > as Power, however, disabling grouping of events always reduces the >> > > > > number of events. >> > > > > >> > > > > The result for Memory_BW needs explanation: >> > > > > >> > > > > Metric group: Memory_BW >> > > > > - No merging (old default, now --metric-no-merge): 9 >> > > > > - Merging over metrics (new default) : 5 >> > > > > - No event groups and merging (--metric-no-group): 11 >> > > > > >> > > > > Both with and without merging the groups fail to be set up and so the >> > > > > event counts here are for broken metrics. The --metric-no-group number >> > > > > is accurate as all the events are scheduled. Ideally a constraint >> > > > > would be added for these metrics in the json code to avoid grouping. >> > > > > >> > > > > v2. rebases on kernel/git/acme/linux.git branch tmp.perf/core, fixes a >> > > > > missing comma with metric lists (reported-by Jiri Olsa >> > > > > <jolsa@xxxxxxxxxx>) and adds early returns to metricgroup__add_metric >> > > > > (suggested-by Jiri Olsa). >> > > > >> > > > Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx> >> > > >> > > Applied and pushed to tmp.perf/core, will move to perf/core as soon as >> > > testing finishes, >> > >> > I checked tmp.perf/core and I'm getting segfault for 'perf test expr' >> >> Right, reproduced here and... >> >> > 7: Simple expression parser : >> > Program received signal SIGSEGV, Segmentation fault. >> > 0x000000000067841e in hashmap_find_entry (map=0x7fffffffd0c0, key=0xc83b30, hash=9893851511679796638, pprev=0x0, entry=0x7fffffffc658) at hashmap.c:131 >> > 131 for (prev_ptr = &map->buckets[hash], cur = *prev_ptr; >> > (gdb) bt >> > #0 0x000000000067841e in hashmap_find_entry (map=0x7fffffffd0c0, key=0xc83b30, hash=9893851511679796638, pprev=0x0, entry=0x7fffffffc658) at hashmap.c:131 >> > #1 0x000000000067853a in hashmap__insert (map=0x7fffffffd0c0, key=0xc83b30, value=0x0, strategy=HASHMAP_SET, old_key=0x7fffffffc718, >> > old_value=0x7fffffffc710) at hashmap.c:160 >> > #2 0x00000000005d3209 in hashmap__set (map=0x7fffffffd0c0, key=0xc83b30, value=0x0, old_key=0x7fffffffc718, old_value=0x7fffffffc710) >> > at /home/jolsa/kernel/linux-perf/tools/perf/util/hashmap.h:107 >> > #3 0x00000000005d3386 in expr__add_id (ctx=0x7fffffffd0c0, name=0xc83b30 "FOO", val=0) at util/expr.c:45 >> > #4 0x00000000005d27ee in expr_parse (final_val=0x0, ctx=0x7fffffffd0c0, scanner=0xc87990) at util/expr.y:63 >> > #5 0x00000000005d35b7 in __expr__parse (val=0x0, ctx=0x7fffffffd0c0, expr=0x75a84b "FOO + BAR + BAZ + BOZO", start=259, runtime=1) at util/expr.c:102 >> > #6 0x00000000005d36c6 in expr__find_other (expr=0x75a84b "FOO + BAR + BAZ + BOZO", one=0x75a791 "FOO", ctx=0x7fffffffd0c0, runtime=1) at util/expr.c:121 >> > #7 0x00000000004e3aaf in test__expr (t=0xa7bd40 <generic_tests+384>, subtest=-1) at tests/expr.c:55 >> > #8 0x00000000004b5651 in run_test (test=0xa7bd40 <generic_tests+384>, subtest=-1) at tests/builtin-test.c:393 >> > #9 0x00000000004b5787 in test_and_print (t=0xa7bd40 <generic_tests+384>, force_skip=false, subtest=-1) at tests/builtin-test.c:423 >> > #10 0x00000000004b61c4 in __cmd_test (argc=1, argv=0x7fffffffd7f0, skiplist=0x0) at tests/builtin-test.c:628 >> > #11 0x00000000004b6911 in cmd_test (argc=1, argv=0x7fffffffd7f0) at tests/builtin-test.c:772 >> > #12 0x00000000004e977b in run_builtin (p=0xa7eee8 <commands+552>, argc=3, argv=0x7fffffffd7f0) at perf.c:312 >> > #13 0x00000000004e99e8 in handle_internal_command (argc=3, argv=0x7fffffffd7f0) at perf.c:364 >> > #14 0x00000000004e9b2f in run_argv (argcp=0x7fffffffd64c, argv=0x7fffffffd640) at perf.c:408 >> > #15 0x00000000004e9efb in main (argc=3, argv=0x7fffffffd7f0) at perf.c:538 >> > >> > attached patch fixes it for me, but I'm not sure this >> > should be necessary >> >> ... applying the patch below makes the segfault go away. Ian, Ack? I can >> fold it into the patch introducing the problem. > > > I suspect this patch is a memory leak. The underlying issue is likely the outstanding hashmap_clear fix in libbpf. Let me check. > > Thanks, > Ian Tested: $ git checkout -b testing acme/tmp.perf/core $ make ... $ perf test 7 7: Simple expression parser : FAILED! $ git cherry-pick 6bca339175bf [acme-perf-expr-testing 4614bd252003] libbpf: Fix memory leak and possible double-free in hashmap__c lear Author: Andrii Nakryiko <andriin@xxxxxx> Date: Tue Apr 28 18:21:04 2020 -0700 1 file changed, 7 insertions(+) $ make ... $ perf test 7 7: Simple expression parser : Ok I'd prefer we took the libbpf fix as initializing over the top of the hashmap will leak. This fix is in the tools/perf/util/hashmap.c. Thanks, Ian >> - Arnaldo >> >> > jirka >> > >> > >> > --- >> > diff --git a/tools/perf/tests/expr.c b/tools/perf/tests/expr.c >> > index 1cb02ca2b15f..21693fe516c1 100644 >> > --- a/tools/perf/tests/expr.c >> > +++ b/tools/perf/tests/expr.c >> > @@ -52,6 +52,7 @@ int test__expr(struct test *t __maybe_unused, int subtest __maybe_unused) >> > TEST_ASSERT_VAL("missing operand", ret == -1); >> > >> > expr__ctx_clear(&ctx); >> > + expr__ctx_init(&ctx); >> > TEST_ASSERT_VAL("find other", >> > expr__find_other("FOO + BAR + BAZ + BOZO", "FOO", >> > &ctx, 1) == 0); >> > @@ -64,6 +65,7 @@ int test__expr(struct test *t __maybe_unused, int subtest __maybe_unused) >> > (void **)&val_ptr)); >> > >> > expr__ctx_clear(&ctx); >> > + expr__ctx_init(&ctx); >> > TEST_ASSERT_VAL("find other", >> > expr__find_other("EVENT1\\,param\\=?@ + EVENT2\\,param\\=?@", >> > NULL, &ctx, 3) == 0); >> > >> > >> >> -- >> >> - Arnaldo