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authorStephane Eranian <eranian@google.com>2015-08-31 18:41:12 +0200
committerArnaldo Carvalho de Melo <acme@redhat.com>2015-08-31 18:01:33 -0300
commitbcc84ec65ad1bd9f777a1fade6f8e5e0c5808fa5 (patch)
treef824e46632026abbbe0f76f109e86b2c09bec18f /tools
parentc5e991ee9dff0f8136168ed2d0d1a8cc3620dac4 (diff)
downloadlinux-bcc84ec65ad1bd9f777a1fade6f8e5e0c5808fa5.tar.gz
perf record: Add ability to name registers to record
This patch modifies the -I/--int-regs option to enablepassing the name of the registers to sample on interrupt. Registers can be specified by their symbolic names. For instance on x86, --intr-regs=ax,si. The motivation is to reduce the size of the perf.data file and the overhead of sampling by only collecting the registers useful to a specific analysis. For instance, for value profiling, sampling only the registers used to passed arguements to functions. With no parameter, the --intr-regs still records all possible registers based on the architecture. To name registers, it is necessary to use the long form of the option, i.e., --intr-regs: $ perf record --intr-regs=si,di,r8,r9 ..... To record any possible registers: $ perf record -I ..... $ perf report --intr-regs ... To display the register, one can use perf report -D To list the available registers: $ perf record --intr-regs=\? available registers: AX BX CX DX SI DI BP SP IP FLAGS CS SS R8 R9 R10 R11 R12 R13 R14 R15 Signed-off-by: Stephane Eranian <eranian@google.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1441039273-16260-4-git-send-email-eranian@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
-rw-r--r--tools/perf/Documentation/perf-record.txt6
-rw-r--r--tools/perf/builtin-record.c7
-rw-r--r--tools/perf/perf.h2
-rw-r--r--tools/perf/util/Build1
-rw-r--r--tools/perf/util/evsel.c2
-rw-r--r--tools/perf/util/parse-regs-options.c71
-rw-r--r--tools/perf/util/parse-regs-options.h5
7 files changed, 89 insertions, 5 deletions
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 347a27322ed8..2e9ce77b5e14 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -276,7 +276,11 @@ filter out the startup phase of the program, which is often very different.
--intr-regs::
Capture machine state (registers) at interrupt, i.e., on counter overflows for
each sample. List of captured registers depends on the architecture. This option
-is off by default.
+is off by default. It is possible to select the registers to sample using their
+symbolic names, e.g. on x86, ax, si. To list the available registers use
+--intr-regs=\?. To name registers, pass a comma separated list such as
+--intr-regs=ax,bx. The list of register is architecture dependent.
+
--running-time::
Record running and enabled time for read events (:S)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 1d14f382f614..142eeb341b29 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -27,8 +27,10 @@
#include "util/cpumap.h"
#include "util/thread_map.h"
#include "util/data.h"
+#include "util/perf_regs.h"
#include "util/auxtrace.h"
#include "util/parse-branch-options.h"
+#include "util/parse-regs-options.h"
#include <unistd.h>
#include <sched.h>
@@ -1080,8 +1082,9 @@ struct option __record_options[] = {
"sample transaction flags (special events only)"),
OPT_BOOLEAN(0, "per-thread", &record.opts.target.per_thread,
"use per-thread mmaps"),
- OPT_BOOLEAN('I', "intr-regs", &record.opts.sample_intr_regs,
- "Sample machine registers on interrupt"),
+ OPT_CALLBACK_OPTARG('I', "intr-regs", &record.opts.sample_intr_regs, NULL, "any register",
+ "sample selected machine registers on interrupt,"
+ " use -I ? to list register names", parse_regs),
OPT_BOOLEAN(0, "running-time", &record.opts.running_time,
"Record running/enabled time of read (:S) events"),
OPT_CALLBACK('k', "clockid", &record.opts,
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index cccb4cf575d3..90129accffbe 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -54,7 +54,6 @@ struct record_opts {
bool sample_time_set;
bool callgraph_set;
bool period;
- bool sample_intr_regs;
bool running_time;
bool full_auxtrace;
bool auxtrace_snapshot_mode;
@@ -64,6 +63,7 @@ struct record_opts {
unsigned int auxtrace_mmap_pages;
unsigned int user_freq;
u64 branch_stack;
+ u64 sample_intr_regs;
u64 default_interval;
u64 user_interval;
size_t auxtrace_snapshot_size;
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index e79e4522368a..349bc96ca1fe 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -83,6 +83,7 @@ libperf-$(CONFIG_AUXTRACE) += intel-pt-decoder/
libperf-$(CONFIG_AUXTRACE) += intel-pt.o
libperf-$(CONFIG_AUXTRACE) += intel-bts.o
libperf-y += parse-branch-options.o
+libperf-y += parse-regs-options.o
libperf-$(CONFIG_LIBELF) += symbol-elf.o
libperf-$(CONFIG_LIBELF) += probe-file.o
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index bac25f41a751..c53f79123b37 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -787,7 +787,7 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts)
perf_evsel__config_callgraph(evsel, opts, &callchain_param);
if (opts->sample_intr_regs) {
- attr->sample_regs_intr = PERF_REGS_MASK;
+ attr->sample_regs_intr = opts->sample_intr_regs;
perf_evsel__set_sample_bit(evsel, REGS_INTR);
}
diff --git a/tools/perf/util/parse-regs-options.c b/tools/perf/util/parse-regs-options.c
new file mode 100644
index 000000000000..4f2c1c255d81
--- /dev/null
+++ b/tools/perf/util/parse-regs-options.c
@@ -0,0 +1,71 @@
+#include "perf.h"
+#include "util/util.h"
+#include "util/debug.h"
+#include "util/parse-options.h"
+#include "util/parse-regs-options.h"
+
+int
+parse_regs(const struct option *opt, const char *str, int unset)
+{
+ uint64_t *mode = (uint64_t *)opt->value;
+ const struct sample_reg *r;
+ char *s, *os = NULL, *p;
+ int ret = -1;
+
+ if (unset)
+ return 0;
+
+ /*
+ * cannot set it twice
+ */
+ if (*mode)
+ return -1;
+
+ /* str may be NULL in case no arg is passed to -I */
+ if (str) {
+ /* because str is read-only */
+ s = os = strdup(str);
+ if (!s)
+ return -1;
+
+ for (;;) {
+ p = strchr(s, ',');
+ if (p)
+ *p = '\0';
+
+ if (!strcmp(s, "?")) {
+ fprintf(stderr, "available registers: ");
+ for (r = sample_reg_masks; r->name; r++) {
+ fprintf(stderr, "%s ", r->name);
+ }
+ fputc('\n', stderr);
+ /* just printing available regs */
+ return -1;
+ }
+ for (r = sample_reg_masks; r->name; r++) {
+ if (!strcasecmp(s, r->name))
+ break;
+ }
+ if (!r->name) {
+ ui__warning("unknown register %s,"
+ " check man page\n", s);
+ goto error;
+ }
+
+ *mode |= r->mask;
+
+ if (!p)
+ break;
+
+ s = p + 1;
+ }
+ }
+ ret = 0;
+
+ /* default to all possible regs */
+ if (*mode == 0)
+ *mode = PERF_REGS_MASK;
+error:
+ free(os);
+ return ret;
+}
diff --git a/tools/perf/util/parse-regs-options.h b/tools/perf/util/parse-regs-options.h
new file mode 100644
index 000000000000..7d762b188007
--- /dev/null
+++ b/tools/perf/util/parse-regs-options.h
@@ -0,0 +1,5 @@
+#ifndef _PERF_PARSE_REGS_OPTIONS_H
+#define _PERF_PARSE_REGS_OPTIONS_H 1
+struct option;
+int parse_regs(const struct option *opt, const char *str, int unset);
+#endif /* _PERF_PARSE_REGS_OPTIONS_H */