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Date: Tue, 16 Dec 2014 16:00:51 -0500
From: Stephane Eranian <eranian@...gle.com>
To: Arnaldo Carvalho de Melo <acme@...hat.com>
Cc: LKML <linux-kernel@...r.kernel.org>,
Peter Zijlstra <peterz@...radead.org>,
"mingo@...e.hu" <mingo@...e.hu>,
"ak@...ux.intel.com" <ak@...ux.intel.com>,
Jiri Olsa <jolsa@...hat.com>, David Ahern <dsahern@...il.com>,
Don Zickus <dzickus@...hat.com>,
Namhyung Kim <namhyung@...nel.org>,
Joe Mario <jmario@...hat.com>,
Richard Fowles <rfowles@...hat.com>
Subject: Re: [PATCH] perf mem: enable simultaneous sampling of loads/stores
On Tue, Dec 16, 2014 at 3:44 PM, Arnaldo Carvalho de Melo
<acme@...hat.com> wrote:
>
> Em Tue, Dec 16, 2014 at 05:53:58PM +0100, Stephane Eranian escreveu:
> >
> > This patch modifies perf mem to default to sampling loads
> > and stores simultaneously. It could only do one or the other
> > before yet there was not hardware restriction preventing
> > simultaneous collection. With this patch, one run is sufficient
> > to collect both.
> >
> > By default load/stores are sampled now:
> > $ perf mem rec
> > $ perf mem rep
> >
> > It is still possible to sample only loads or stores by using the
> > -t option:
> > $ perf mem -t load rec
> > $ perf mem -t load rep
> > Or
> > $ perf mem -t store rec
> > $ perf mem -t store rep
> >
> > The perf report TUI will show one event at a time. The store
> > output will contain a Weight column which will be empty.
>
> Can you please update the man page and resubmit?
>
Ok, will do that.
>
> Are those unchecked strdups really needed?
>
Well, it all boils down to how cmd_xx() declares argv:
- const char **argv
- char *argv
If the latter, then cannot simply do rec[i++] = "report"
otherwise we may crash it the ever decides to modify that string.
Given that cmd_record() and cmd_report() use const char *argv, then
I can use literals. Right?
>
> - Arnaldo
>
> > Signed-off-by: Stephane Eranian <eranian@...gle.com>
> > ---
> > tools/perf/builtin-mem.c | 107 ++++++++++++++++++++++++++++++++++++++++-------
> > 1 file changed, 92 insertions(+), 15 deletions(-)
> >
> > diff --git a/tools/perf/builtin-mem.c b/tools/perf/builtin-mem.c
> > index 24db6ff..52dbaae 100644
> > --- a/tools/perf/builtin-mem.c
> > +++ b/tools/perf/builtin-mem.c
> > @@ -7,10 +7,13 @@
> > #include "util/session.h"
> > #include "util/data.h"
> >
> > -#define MEM_OPERATION_LOAD "load"
> > -#define MEM_OPERATION_STORE "store"
> > +#define MEM_OPERATION_LOAD 0x1
> > +#define MEM_OPERATION_STORE 0x2
> >
> > -static const char *mem_operation = MEM_OPERATION_LOAD;
> > +/*
> > + * default to both load an store sampling
> > + */
> > +static int mem_operation = MEM_OPERATION_LOAD | MEM_OPERATION_STORE;
> >
> > struct perf_mem {
> > struct perf_tool tool;
> > @@ -25,26 +28,30 @@ static int __cmd_record(int argc, const char **argv)
> > {
> > int rec_argc, i = 0, j;
> > const char **rec_argv;
> > - char event[64];
> > int ret;
> >
> > - rec_argc = argc + 4;
> > + rec_argc = argc + 7; /* max number of arguments */
> > rec_argv = calloc(rec_argc + 1, sizeof(char *));
> > if (!rec_argv)
> > return -1;
> >
> > rec_argv[i++] = strdup("record");
> > - if (!strcmp(mem_operation, MEM_OPERATION_LOAD))
> > +
> > + if (mem_operation & MEM_OPERATION_LOAD)
> > rec_argv[i++] = strdup("-W");
> > +
> > rec_argv[i++] = strdup("-d");
> > - rec_argv[i++] = strdup("-e");
> >
> > - if (strcmp(mem_operation, MEM_OPERATION_LOAD))
> > - sprintf(event, "cpu/mem-stores/pp");
> > - else
> > - sprintf(event, "cpu/mem-loads/pp");
> > + if (mem_operation & MEM_OPERATION_LOAD) {
> > + rec_argv[i++] = strdup("-e");
> > + rec_argv[i++] = strdup("cpu/mem-loads/pp");
> > + }
> > +
> > + if (mem_operation & MEM_OPERATION_STORE) {
> > + rec_argv[i++] = strdup("-e");
> > + rec_argv[i++] = strdup("cpu/mem-stores/pp");
> > + }
> >
> > - rec_argv[i++] = strdup(event);
> > for (j = 1; j < argc; j++, i++)
> > rec_argv[i] = argv[j];
> >
> > @@ -170,7 +177,7 @@ static int report_events(int argc, const char **argv, struct perf_mem *mem)
> > * there is no weight (cost) associated with stores, so don't print
> > * the column
> > */
> > - if (strcmp(mem_operation, MEM_OPERATION_LOAD))
> > + if (!(mem_operation & MEM_OPERATION_LOAD))
> > rep_argv[i++] = strdup("--sort=mem,sym,dso,symbol_daddr,"
> > "dso_daddr,tlb,locked");
> >
> > @@ -182,6 +189,75 @@ static int report_events(int argc, const char **argv, struct perf_mem *mem)
> > return ret;
> > }
> >
> > +struct mem_mode {
> > + const char *name;
> > + int mode;
> > +};
> > +
> > +#define MEM_OPT(n, m) \
> > + { .name = n, .mode = (m) }
> > +
> > +#define MEM_END { .name = NULL }
> > +
> > +static const struct mem_mode mem_modes[]={
> > + MEM_OPT("load", MEM_OPERATION_LOAD),
> > + MEM_OPT("store", MEM_OPERATION_STORE),
> > + MEM_END
> > +};
> > +
> > +static int
> > +parse_mem_ops(const struct option *opt, const char *str, int unset)
> > +{
> > + int *mode = (int *)opt->value;
> > + const struct mem_mode *m;
> > + char *s, *os = NULL, *p;
> > + int ret = -1;
> > +
> > + if (unset)
> > + return 0;
> > +
> > + /* str may be NULL in case no arg is passed to -t */
> > + if (str) {
> > + /* because str is read-only */
> > + s = os = strdup(str);
> > + if (!s)
> > + return -1;
> > +
> > + /* reset mode */
> > + *mode = 0;
> > +
> > + for (;;) {
> > + p = strchr(s, ',');
> > + if (p)
> > + *p = '\0';
> > +
> > + for (m = mem_modes; m->name; m++) {
> > + if (!strcasecmp(s, m->name))
> > + break;
> > + }
> > + if (!m->name) {
> > + fprintf(stderr, "unknown sampling op %s,"
> > + " check man page\n", s);
> > + goto error;
> > + }
> > +
> > + *mode |= m->mode;
> > +
> > + if (!p)
> > + break;
> > +
> > + s = p + 1;
> > + }
> > + }
> > + ret = 0;
> > +
> > + if (*mode == 0)
> > + *mode = MEM_OPERATION_LOAD;
> > +error:
> > + free(os);
> > + return ret;
> > +}
> > +
> > int cmd_mem(int argc, const char **argv, const char *prefix __maybe_unused)
> > {
> > struct stat st;
> > @@ -199,8 +275,9 @@ int cmd_mem(int argc, const char **argv, const char *prefix __maybe_unused)
> > .input_name = "perf.data",
> > };
> > const struct option mem_options[] = {
> > - OPT_STRING('t', "type", &mem_operation,
> > - "type", "memory operations(load/store)"),
> > + OPT_CALLBACK('t', "type", &mem_operation,
> > + "type", "memory operations(load,store) Default load,store",
> > + parse_mem_ops),
> > OPT_BOOLEAN('D', "dump-raw-samples", &mem.dump_raw,
> > "dump raw samples in ASCII"),
> > OPT_BOOLEAN('U', "hide-unresolved", &mem.hide_unresolved,
> > --
> > 1.9.1
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