[PATCH 15/28] perf kvm: Switch to new perf_mmap__read_event() interface

Arnaldo Carvalho de Melo
2018-03-05T14:34:49Z

From: Kan Liang <kan.liang@linux.intel.com>

The perf kvm still use the legacy interface.

Switch to the new perf_mmap__read_event() interface for perf kvm.

No functional change.

Committer notes:

Tested before and after running:

# perf kvm stat record

On a machine with a kvm guest, then used:

# perf kvm stat report

Before/after results match and look like:

# perf kvm stat record -a sleep 5
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 2.132 MB perf.data.guest (1828 samples) ]
# perf kvm stat report

Analyze events for all VMs, all VCPUs:

VM-EXIT Samples Samples% Time% Min Time Max Time Avg time

IO_INSTRUCTION 258 40.06% 0.08% 3.51us 122.54us 14.87us (+- 6.76%)
MSR_WRITE 178 27.64% 0.01% 0.47us 6.34us 2.18us (+- 4.80%)
EPT_MISCONFIG 148 22.98% 0.03% 3.76us 65.60us 11.22us (+- 8.14%)
HLT 47 7.30% 99.88% 181.69us 249988.06us 102061.36us (+-13.49%)
PAUSE_INSTRUCTION 5 0.78% 0.00% 0.38us 0.79us 0.47us (+-17.05%)
MSR_READ 4 0.62% 0.00% 1.14us 3.33us 2.67us (+-19.35%)
EXTERNAL_INTERRUPT 2 0.31% 0.00% 2.15us 2.17us 2.16us (+- 0.30%)
PENDING_INTERRUPT 1 0.16% 0.00% 2.56us 2.56us 2.56us (+- 0.00%)
PREEMPTION_TIMER 1 0.16% 0.00% 3.21us 3.21us 3.21us (+- 0.00%)

Total Samples:644, Total events handled time:4802790.72us.

#

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1519945751-37786-1-git-send-email-kan.liang@linux.intel.com
[ Changed bool parameters from 0 to 'false', as per Jiri comment ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/builtin-kvm.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index 55d919dc5bc6..d2703d3b8366 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -743,16 +743,24 @@ static bool verify_vcpu(int vcpu)
static s64 perf_kvm__mmap_read_idx(struct perf_kvm_stat *kvm, int idx,
u64 *mmap_time)
{
+ struct perf_evlist *evlist = kvm->evlist;
union perf_event *event;
+ struct perf_mmap *md;
+ u64 end, start;
u64 timestamp;
s64 n = 0;
int err;

*mmap_time = ULLONG_MAX;
- while ((event = perf_evlist__mmap_read(kvm->evlist, idx)) != NULL) {
- err = perf_evlist__parse_sample_timestamp(kvm->evlist, event, &timestamp);
+ md = &evlist->mmap[idx];
+ err = perf_mmap__read_init(md, false, &start, &end);
+ if (err < 0)
+ return (err == -EAGAIN) ? 0 : -1;
+
+ while ((event = perf_mmap__read_event(md, false, &start, end)) != NULL) {
+ err = perf_evlist__parse_sample_timestamp(evlist, event, &timestamp);
if (err) {
- perf_evlist__mmap_consume(kvm->evlist, idx);
+ perf_mmap__consume(md, false);
pr_err("Failed to parse sample\n");
return -1;
}
@@ -762,7 +770,7 @@ static s64 perf_kvm__mmap_read_idx(struct perf_kvm_stat *kvm, int idx,
* FIXME: Here we can't consume the event, as perf_session__queue_event will
* point to it, and it'll get possibly overwritten by the kernel.
*/
- perf_evlist__mmap_consume(kvm->evlist, idx);
+ perf_mmap__consume(md, false);

if (err) {
pr_err("Failed to enqueue sample: %d\n", err);
@@ -779,6 +787,7 @@ static s64 perf_kvm__mmap_read_idx(struct perf_kvm_stat *kvm, int idx,
break;
}

+ perf_mmap__read_done(md);
return n;
}

--
2.14.3