forked from Minki/linux
bcc84ec65a
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>
72 lines
1.2 KiB
C
72 lines
1.2 KiB
C
#include "perf.h"
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#include "util/util.h"
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#include "util/debug.h"
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#include "util/parse-options.h"
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#include "util/parse-regs-options.h"
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int
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parse_regs(const struct option *opt, const char *str, int unset)
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{
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uint64_t *mode = (uint64_t *)opt->value;
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const struct sample_reg *r;
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char *s, *os = NULL, *p;
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int ret = -1;
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if (unset)
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return 0;
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/*
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* cannot set it twice
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*/
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if (*mode)
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return -1;
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/* str may be NULL in case no arg is passed to -I */
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if (str) {
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/* because str is read-only */
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s = os = strdup(str);
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if (!s)
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return -1;
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for (;;) {
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p = strchr(s, ',');
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if (p)
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*p = '\0';
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if (!strcmp(s, "?")) {
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fprintf(stderr, "available registers: ");
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for (r = sample_reg_masks; r->name; r++) {
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fprintf(stderr, "%s ", r->name);
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}
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fputc('\n', stderr);
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/* just printing available regs */
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return -1;
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}
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for (r = sample_reg_masks; r->name; r++) {
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if (!strcasecmp(s, r->name))
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break;
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}
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if (!r->name) {
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ui__warning("unknown register %s,"
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" check man page\n", s);
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goto error;
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}
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*mode |= r->mask;
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if (!p)
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break;
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s = p + 1;
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}
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}
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ret = 0;
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/* default to all possible regs */
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if (*mode == 0)
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*mode = PERF_REGS_MASK;
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error:
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free(os);
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return ret;
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}
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