Messages in this thread | | | Date | Fri, 14 Aug 2020 09:47:22 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH v3] perf parse-events: Set exclude_guest=1 for user-space counting |
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Em Fri, Aug 14, 2020 at 09:21:20AM +0800, Jin Yao escreveu: > Currently if we run 'perf record -e cycles:u', exclude_guest=0. > > But it doesn't make sense in most cases that we request for > user-space counting but we also get the guest report. > > Of course, we also need to consider perf kvm usage case that > authorized perf users on the host may only want to count guest > user space events. For example, > > perf kvm --guest record -e cycles:u
Ok, probably this works, but what if I want to record guest user samples without using 'perf kvm'?
Can we have a 'U' modifier, perhaps, for that?
I.e.
perf record -e cycles:uU would not set exclude_host not exclude_guest, cycles:u excludes guest user, cycles:U excludes host user, would that be possible?
Anyway, I think that with what we have, your patch makes sense, having a way to, without using 'perf kvm' still be able to sample the guest can be done on top. of this.
Xu, can we get your Reviewed-by if this addresses your concerns?
- Arnaldo
> When we have 'exclude_guest=1' for perf kvm usage, we may get > nothing from guest events. > > To keep perf semantics consistent and clear, this patch sets > exclude_guest=1 for user-space counting but except for perf > kvm usage. > > Before: > perf record -e cycles:u ./div > perf evlist -v > cycles:u: ..., exclude_kernel: 1, exclude_hv: 1, ... > > After: > perf record -e cycles:u ./div > perf evlist -v > cycles:u: ..., exclude_kernel: 1, exclude_hv: 1, exclude_guest: 1, ... > > Before: > perf kvm --guest record -e cycles:u -vvv > > perf_event_attr: > size 120 > { sample_period, sample_freq } 4000 > sample_type IP|TID|TIME|ID|CPU|PERIOD > read_format ID > disabled 1 > inherit 1 > exclude_kernel 1 > exclude_hv 1 > freq 1 > sample_id_all 1 > > After: > perf kvm --guest record -e cycles:u -vvv > > perf_event_attr: > size 120 > { sample_period, sample_freq } 4000 > sample_type IP|TID|TIME|ID|CPU|PERIOD > read_format ID > disabled 1 > inherit 1 > exclude_kernel 1 > exclude_hv 1 > freq 1 > sample_id_all 1 > > For Before/After, exclude_guest are both 0 for perf kvm usage. > > perf test 6 > 6: Parse event definition strings : Ok > > Signed-off-by: Jin Yao <yao.jin@linux.intel.com> > --- > v3: > --- > For perf kvm, if we have 'exclude_guest=1', we can't get guest > events. So we don't set 'exclude_guest=1' for perf kvm. > > v2: > --- > Fix the 'perf test 6' failure. > > tools/perf/tests/parse-events.c | 4 ++-- > tools/perf/util/parse-events.c | 3 +++ > 2 files changed, 5 insertions(+), 2 deletions(-) > > diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c > index 7f9f87a470c3..aae0fd9045c1 100644 > --- a/tools/perf/tests/parse-events.c > +++ b/tools/perf/tests/parse-events.c > @@ -719,7 +719,7 @@ static int test__group2(struct evlist *evlist) > TEST_ASSERT_VAL("wrong exclude_user", !evsel->core.attr.exclude_user); > TEST_ASSERT_VAL("wrong exclude_kernel", !evsel->core.attr.exclude_kernel); > TEST_ASSERT_VAL("wrong exclude_hv", evsel->core.attr.exclude_hv); > - TEST_ASSERT_VAL("wrong exclude guest", !evsel->core.attr.exclude_guest); > + TEST_ASSERT_VAL("wrong exclude guest", evsel->core.attr.exclude_guest); > TEST_ASSERT_VAL("wrong exclude host", !evsel->core.attr.exclude_host); > TEST_ASSERT_VAL("wrong precise_ip", !evsel->core.attr.precise_ip); > TEST_ASSERT_VAL("wrong leader", evsel__is_group_leader(evsel)); > @@ -842,7 +842,7 @@ static int test__group3(struct evlist *evlist __maybe_unused) > TEST_ASSERT_VAL("wrong exclude_user", !evsel->core.attr.exclude_user); > TEST_ASSERT_VAL("wrong exclude_kernel", evsel->core.attr.exclude_kernel); > TEST_ASSERT_VAL("wrong exclude_hv", evsel->core.attr.exclude_hv); > - TEST_ASSERT_VAL("wrong exclude guest", !evsel->core.attr.exclude_guest); > + TEST_ASSERT_VAL("wrong exclude guest", evsel->core.attr.exclude_guest); > TEST_ASSERT_VAL("wrong exclude host", !evsel->core.attr.exclude_host); > TEST_ASSERT_VAL("wrong precise_ip", !evsel->core.attr.precise_ip); > TEST_ASSERT_VAL("wrong leader", evsel__is_group_leader(evsel)); > diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c > index 9f7260e69113..ff4c23d2a0f3 100644 > --- a/tools/perf/util/parse-events.c > +++ b/tools/perf/util/parse-events.c > @@ -37,6 +37,7 @@ > #include "util/evsel_config.h" > #include "util/event.h" > #include "util/pfm.h" > +#include "perf.h" > > #define MAX_NAME_LEN 100 > > @@ -1794,6 +1795,8 @@ static int get_event_modifier(struct event_modifier *mod, char *str, > if (*str == 'u') { > if (!exclude) > exclude = eu = ek = eh = 1; > + if (!exclude_GH && !perf_guest) > + eG = 1; > eu = 0; > } else if (*str == 'k') { > if (!exclude) > -- > 2.17.1 >
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- Arnaldo
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