Allow requesting high-order AUX allocations from the perf record command
line. Since this operation requires CAP_SYS_ADMIN, adjust the error message
to suggest this as a potential reason of failure.
Signed-off-by: Alexander Shishkin <alexander.shish...@linux.intel.com>
---
tools/include/uapi/linux/perf_event.h | 3 ++-
tools/perf/builtin-record.c | 2 ++
tools/perf/perf.h | 1 +
tools/perf/util/evsel.c | 9 +++++++++
4 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/tools/include/uapi/linux/perf_event.h
b/tools/include/uapi/linux/perf_event.h
index 7198ddd0c6b1..04726b5729c8 100644
--- a/tools/include/uapi/linux/perf_event.h
+++ b/tools/include/uapi/linux/perf_event.h
@@ -374,7 +374,8 @@ struct perf_event_attr {
namespaces : 1, /* include namespaces data
*/
ksymbol : 1, /* include ksymbol events
*/
bpf_event : 1, /* include bpf events */
- __reserved_1 : 33;
+ aux_highorder : 1, /* use high order
allocations for AUX data */
+ __reserved_1 : 32;
union {
__u32 wakeup_events; /* wakeup every n events */
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 3fdfbaebd95e..9f8d5eba24a8 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1929,6 +1929,8 @@ static struct option __record_options[] = {
parse_clockid),
OPT_STRING_OPTARG('S', "snapshot", &record.opts.auxtrace_snapshot_opts,
"opts", "AUX area tracing Snapshot Mode", ""),
+ OPT_BOOLEAN(0, "aux-highorder", &record.opts.aux_highorder,
+ "Use high-order allocation for AUX buffers"),
OPT_UINTEGER(0, "proc-map-timeout", &proc_map_timeout,
"per thread proc mmap processing timeout in ms"),
OPT_BOOLEAN(0, "namespaces", &record.opts.record_namespaces,
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index b120e547ddc7..42f1fa5faeed 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -67,6 +67,7 @@ struct record_opts {
bool strict_freq;
bool sample_id;
bool bpf_event;
+ bool aux_highorder;
unsigned int freq;
unsigned int mmap_pages;
unsigned int auxtrace_mmap_pages;
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 684c893ca6bc..3f4dc8f79d2f 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1098,6 +1098,9 @@ void perf_evsel__config(struct perf_evsel *evsel, struct
record_opts *opts,
if (evsel->own_cpus || evsel->unit)
evsel->attr.read_format |= PERF_FORMAT_ID;
+ if (opts->aux_highorder)
+ attr->aux_highorder = 1;
+
/*
* Apply event specific term settings,
* it overloads any global configuration.
@@ -1657,6 +1660,7 @@ int perf_event_attr__fprintf(FILE *fp, struct
perf_event_attr *attr,
PRINT_ATTRf(namespaces, p_unsigned);
PRINT_ATTRf(ksymbol, p_unsigned);
PRINT_ATTRf(bpf_event, p_unsigned);
+ PRINT_ATTRf(aux_highorder, p_unsigned);
PRINT_ATTRn("{ wakeup_events, wakeup_watermark }", wakeup_events,
p_unsigned);
PRINT_ATTRf(bp_type, p_unsigned);
@@ -2891,6 +2895,11 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel,
struct target *target,
"No permission to enable %s event.\n\n",
perf_evsel__name(evsel));
+ if (evsel->attr.aux_highorder)
+ printed += scnprintf(msg + printed, size - printed,
+ "Using --aux-highorder may not be
possible with your privilege level,\n"
+ "which requires CAP_SYS_ADMIN
capability. Consider using sudo.\n\n");
+
return scnprintf(msg + printed, size - printed,
"You may not have permission to collect %sstats.\n\n"
"Consider tweaking /proc/sys/kernel/perf_event_paranoid,\n"
--
2.20.1
