linux/tools/perf/util/dso.h
Waiman Long f9ceffb605 perf symbols: Fix vdso list searching
When "perf record" was used on a large machine with a lot of CPUs, the
perf post-processing time (the time after the workload was done until
the perf command itself exited) could take a lot of minutes and even
hours depending on how large the resulting perf.data file was.

While running AIM7 1500-user high_systime workload on a 80-core x86-64
system with a 3.9 kernel (with only the -s -a options used), the
workload itself took about 2 minutes to run and the perf.data file had a
size of 1108.746 MB. However, the post-processing step took more than 10
minutes.

With a gprof-profiled perf binary, the time spent by perf was as
follows:

  %   cumulative   self              self     total
 time   seconds   seconds    calls   s/call   s/call  name
 96.90    822.10   822.10   192156     0.00     0.00  dsos__find
  0.81    828.96     6.86 172089958     0.00     0.00  rb_next
  0.41    832.44     3.48 48539289     0.00     0.00  rb_erase

So 97% (822 seconds) of the time was spent in a single dsos_find()
function. After analyzing the call-graph data below:

 -----------------------------------------------
                 0.00  822.12  192156/192156      map__new [6]
 [7]     96.9    0.00  822.12  192156         vdso__dso_findnew [7]
               822.10    0.00  192156/192156      dsos__find [8]
                 0.01    0.00  192156/192156      dsos__add [62]
                 0.01    0.00  192156/192366      dso__new [61]
                 0.00    0.00       1/45282525     memdup [31]
                 0.00    0.00  192156/192230      dso__set_long_name [91]
 -----------------------------------------------
               822.10    0.00  192156/192156      vdso__dso_findnew [7]
 [8]     96.9  822.10    0.00  192156         dsos__find [8]
 -----------------------------------------------

It was found that the vdso__dso_findnew() function failed to locate
VDSO__MAP_NAME ("[vdso]") in the dso list and have to insert a new
entry at the end for 192156 times. This problem is due to the fact that
there are 2 types of name in the dso entry - short name and long name.
The initial dso__new() adds "[vdso]" to both the short and long names.
After that, vdso__dso_findnew() modifies the long name to something
like /tmp/perf-vdso.so-NoXkDj. The dsos__find() function only compares
the long name. As a result, the same vdso entry is duplicated many
time in the dso list. This bug increases memory consumption as well
as slows the symbol processing time to a crawl.

To resolve this problem, the dsos__find() function interface was
modified to enable searching either the long name or the short
name. The vdso__dso_findnew() will now search only the short name
while the other call sites search for the long name as before.

With this change, the cpu time of perf was reduced from 848.38s to
15.77s and dsos__find() only accounted for 0.06% of the total time.

  0.06     15.73     0.01   192151     0.00     0.00  dsos__find

Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: "Chandramouleeswaran, Aswin" <aswin@hp.com>
Cc: "Norton, Scott J" <scott.norton@hp.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1368110568-64714-1-git-send-email-Waiman.Long@hp.com
[ replaced TRUE/FALSE with stdbool.h equivalents, fixing builds where
  those macros are not present (NO_LIBPYTHON=1 NO_LIBPERL=1), fix from Jiri Olsa ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-07-08 17:59:07 -03:00

150 lines
4.1 KiB
C

#ifndef __PERF_DSO
#define __PERF_DSO
#include <linux/types.h>
#include <linux/rbtree.h>
#include "types.h"
#include "map.h"
enum dso_binary_type {
DSO_BINARY_TYPE__KALLSYMS = 0,
DSO_BINARY_TYPE__GUEST_KALLSYMS,
DSO_BINARY_TYPE__VMLINUX,
DSO_BINARY_TYPE__GUEST_VMLINUX,
DSO_BINARY_TYPE__JAVA_JIT,
DSO_BINARY_TYPE__DEBUGLINK,
DSO_BINARY_TYPE__BUILD_ID_CACHE,
DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
DSO_BINARY_TYPE__GUEST_KMODULE,
DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
DSO_BINARY_TYPE__NOT_FOUND,
};
enum dso_kernel_type {
DSO_TYPE_USER = 0,
DSO_TYPE_KERNEL,
DSO_TYPE_GUEST_KERNEL
};
enum dso_swap_type {
DSO_SWAP__UNSET,
DSO_SWAP__NO,
DSO_SWAP__YES,
};
#define DSO__SWAP(dso, type, val) \
({ \
type ____r = val; \
BUG_ON(dso->needs_swap == DSO_SWAP__UNSET); \
if (dso->needs_swap == DSO_SWAP__YES) { \
switch (sizeof(____r)) { \
case 2: \
____r = bswap_16(val); \
break; \
case 4: \
____r = bswap_32(val); \
break; \
case 8: \
____r = bswap_64(val); \
break; \
default: \
BUG_ON(1); \
} \
} \
____r; \
})
#define DSO__DATA_CACHE_SIZE 4096
#define DSO__DATA_CACHE_MASK ~(DSO__DATA_CACHE_SIZE - 1)
struct dso_cache {
struct rb_node rb_node;
u64 offset;
u64 size;
char data[0];
};
struct dso {
struct list_head node;
struct rb_root symbols[MAP__NR_TYPES];
struct rb_root symbol_names[MAP__NR_TYPES];
struct rb_root cache;
enum dso_kernel_type kernel;
enum dso_swap_type needs_swap;
enum dso_binary_type symtab_type;
enum dso_binary_type data_type;
u8 adjust_symbols:1;
u8 has_build_id:1;
u8 hit:1;
u8 annotate_warned:1;
u8 sname_alloc:1;
u8 lname_alloc:1;
u8 sorted_by_name;
u8 loaded;
u8 build_id[BUILD_ID_SIZE];
const char *short_name;
char *long_name;
u16 long_name_len;
u16 short_name_len;
char name[0];
};
static inline void dso__set_loaded(struct dso *dso, enum map_type type)
{
dso->loaded |= (1 << type);
}
struct dso *dso__new(const char *name);
void dso__delete(struct dso *dso);
void dso__set_short_name(struct dso *dso, const char *name);
void dso__set_long_name(struct dso *dso, char *name);
int dso__name_len(const struct dso *dso);
bool dso__loaded(const struct dso *dso, enum map_type type);
bool dso__sorted_by_name(const struct dso *dso, enum map_type type);
void dso__set_sorted_by_name(struct dso *dso, enum map_type type);
void dso__sort_by_name(struct dso *dso, enum map_type type);
void dso__set_build_id(struct dso *dso, void *build_id);
bool dso__build_id_equal(const struct dso *dso, u8 *build_id);
void dso__read_running_kernel_build_id(struct dso *dso,
struct machine *machine);
int dso__kernel_module_get_build_id(struct dso *dso, const char *root_dir);
char dso__symtab_origin(const struct dso *dso);
int dso__binary_type_file(struct dso *dso, enum dso_binary_type type,
char *root_dir, char *file, size_t size);
int dso__data_fd(struct dso *dso, struct machine *machine);
ssize_t dso__data_read_offset(struct dso *dso, struct machine *machine,
u64 offset, u8 *data, ssize_t size);
ssize_t dso__data_read_addr(struct dso *dso, struct map *map,
struct machine *machine, u64 addr,
u8 *data, ssize_t size);
struct map *dso__new_map(const char *name);
struct dso *dso__kernel_findnew(struct machine *machine, const char *name,
const char *short_name, int dso_type);
void dsos__add(struct list_head *head, struct dso *dso);
struct dso *dsos__find(struct list_head *head, const char *name,
bool cmp_short);
struct dso *__dsos__findnew(struct list_head *head, const char *name);
bool __dsos__read_build_ids(struct list_head *head, bool with_hits);
size_t __dsos__fprintf_buildid(struct list_head *head, FILE *fp,
bool (skip)(struct dso *dso, int parm), int parm);
size_t __dsos__fprintf(struct list_head *head, FILE *fp);
size_t dso__fprintf_buildid(struct dso *dso, FILE *fp);
size_t dso__fprintf_symbols_by_name(struct dso *dso,
enum map_type type, FILE *fp);
size_t dso__fprintf(struct dso *dso, enum map_type type, FILE *fp);
#endif /* __PERF_DSO */