Em Mon, Aug 31, 2015 at 06:41:12PM +0200, Stephane Eranian escreveu: > 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.
Applied and tested up to this one, waiting for the discussion with Andi to proceed to the last one. - Arnaldo > 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 <[email protected]> > --- > tools/perf/Documentation/perf-record.txt | 6 ++- > tools/perf/builtin-record.c | 7 +++- > tools/perf/perf.h | 2 +- > tools/perf/util/Build | 1 + > tools/perf/util/evsel.c | 2 +- > tools/perf/util/parse-regs-options.c | 71 > ++++++++++++++++++++++++++++++++ > tools/perf/util/parse-regs-options.h | 5 +++ > 7 files changed, 89 insertions(+), 5 deletions(-) > create mode 100644 tools/perf/util/parse-regs-options.c > create mode 100644 tools/perf/util/parse-regs-options.h > > diff --git a/tools/perf/Documentation/perf-record.txt > b/tools/perf/Documentation/perf-record.txt > index 347a273..2e9ce77 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 a660022..d3a5d91 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 cccb4cf..90129ac 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 e912856..7df4937 100644 > --- a/tools/perf/util/Build > +++ b/tools/perf/util/Build > @@ -82,6 +82,7 @@ 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 fd53cc2..b049633 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 0000000..4f2c1c2 > --- /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 0000000..7d762b1 > --- /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 */ > -- > 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
