linux/tools/perf/util/probe-finder.h
Lin Ming cd25f8bc26 perf probe: Add fastpath to do lookup by function name
v3 -> v2:
- Make pubname_search_cb more generic
- Add fastpath to find_probes also

v2 -> v1:
- Don't compare file names with cu_find_realpath(...), instead, compare
  them with the name returned by dwarf_decl_file(sp_die)

The vmlinux file may have thousands of CUs.
We can lookup function name from .debug_pubnames section
to avoid the slow loop on CUs.

1. Improvement data for find_line_range

./perf stat -e cycles -r 10 -- ./perf probe -k /home/mlin/vmlinux \
        -s /home/mlin/linux-2.6 \
        --line csum_partial_copy_to_user > tmp.log

before patch applied
=====================
       847,988,276 cycles

        0.355075856  seconds time elapsed

after patch applied
=====================
       206,102,622 cycles

        0.086883555  seconds time elapsed

2. Improvement data for find_probes

./perf stat -e cycles -r 10 -- ./perf probe -k /home/mlin/vmlinux \
        -s /home/mlin/linux-2.6 \
        --vars csum_partial_copy_to_user > tmp.log

before patch applied
=====================
       848,490,844 cycles

        0.355307901  seconds time elapsed

after patch applied
=====================
       205,684,469 cycles

        0.086694010  seconds time elapsed

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: linux-kernel <linux-kernel@vger.kernel.org>
LKML-Reference: <1301041668.14111.52.camel@minggr.sh.intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-03-29 13:40:27 -03:00

94 lines
2.5 KiB
C

#ifndef _PROBE_FINDER_H
#define _PROBE_FINDER_H
#include <stdbool.h>
#include "util.h"
#include "probe-event.h"
#define MAX_PATH_LEN 256
#define MAX_PROBE_BUFFER 1024
#define MAX_PROBES 128
static inline int is_c_varname(const char *name)
{
/* TODO */
return isalpha(name[0]) || name[0] == '_';
}
#ifdef DWARF_SUPPORT
/* Find probe_trace_events specified by perf_probe_event from debuginfo */
extern int find_probe_trace_events(int fd, struct perf_probe_event *pev,
struct probe_trace_event **tevs,
int max_tevs);
/* Find a perf_probe_point from debuginfo */
extern int find_perf_probe_point(unsigned long addr,
struct perf_probe_point *ppt);
/* Find a line range */
extern int find_line_range(int fd, struct line_range *lr);
/* Find available variables */
extern int find_available_vars_at(int fd, struct perf_probe_event *pev,
struct variable_list **vls, int max_points,
bool externs);
#include <dwarf.h>
#include <elfutils/libdw.h>
#include <elfutils/libdwfl.h>
#include <elfutils/version.h>
struct probe_finder {
struct perf_probe_event *pev; /* Target probe event */
/* Callback when a probe point is found */
int (*callback)(Dwarf_Die *sp_die, struct probe_finder *pf);
/* For function searching */
int lno; /* Line number */
Dwarf_Addr addr; /* Address */
const char *fname; /* Real file name */
Dwarf_Die cu_die; /* Current CU */
Dwarf_Die sp_die;
struct list_head lcache; /* Line cache for lazy match */
/* For variable searching */
#if _ELFUTILS_PREREQ(0, 142)
Dwarf_CFI *cfi; /* Call Frame Information */
#endif
Dwarf_Op *fb_ops; /* Frame base attribute */
struct perf_probe_arg *pvar; /* Current target variable */
struct probe_trace_arg *tvar; /* Current result variable */
};
struct trace_event_finder {
struct probe_finder pf;
struct probe_trace_event *tevs; /* Found trace events */
int ntevs; /* Number of trace events */
int max_tevs; /* Max number of trace events */
};
struct available_var_finder {
struct probe_finder pf;
struct variable_list *vls; /* Found variable lists */
int nvls; /* Number of variable lists */
int max_vls; /* Max no. of variable lists */
bool externs; /* Find external vars too */
bool child; /* Search child scopes */
};
struct line_finder {
struct line_range *lr; /* Target line range */
const char *fname; /* File name */
int lno_s; /* Start line number */
int lno_e; /* End line number */
Dwarf_Die cu_die; /* Current CU */
Dwarf_Die sp_die;
int found;
};
#endif /* DWARF_SUPPORT */
#endif /*_PROBE_FINDER_H */