linux/tools/perf/util/symbol.h
Andi Kleen 8b7bad58ef perf callchain: Support handling complete branch stacks as histograms
Currently branch stacks can be only shown as edge histograms for
individual branches. I never found this display particularly useful.

This implements an alternative mode that creates histograms over
complete branch traces, instead of individual branches, similar to how
normal callgraphs are handled. This is done by putting it in front of
the normal callgraph and then using the normal callgraph histogram
infrastructure to unify them.

This way in complex functions we can understand the control flow that
lead to a particular sample, and may even see some control flow in the
caller for short functions.

Example (simplified, of course for such simple code this is usually not
needed), please run this after the whole patchkit is in, as at this
point in the patch order there is no --branch-history, that will be
added in a patch after this one:

tcall.c:

volatile a = 10000, b = 100000, c;

__attribute__((noinline)) f2()
{
	c = a / b;
}

__attribute__((noinline)) f1()
{
	f2();
	f2();
}
main()
{
	int i;
	for (i = 0; i < 1000000; i++)
		f1();
}

% perf record -b -g ./tsrc/tcall
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.044 MB perf.data (~1923 samples) ]
% perf report --no-children --branch-history
...
    54.91%  tcall.c:6  [.] f2                      tcall
            |
            |--65.53%-- f2 tcall.c:5
            |          |
            |          |--70.83%-- f1 tcall.c:11
            |          |          f1 tcall.c:10
            |          |          main tcall.c:18
            |          |          main tcall.c:18
            |          |          main tcall.c:17
            |          |          main tcall.c:17
            |          |          f1 tcall.c:13
            |          |          f1 tcall.c:13
            |          |          f2 tcall.c:7
            |          |          f2 tcall.c:5
            |          |          f1 tcall.c:12
            |          |          f1 tcall.c:12
            |          |          f2 tcall.c:7
            |          |          f2 tcall.c:5
            |          |          f1 tcall.c:11
            |          |
            |           --29.17%-- f1 tcall.c:12
            |                     f1 tcall.c:12
            |                     f2 tcall.c:7
            |                     f2 tcall.c:5
            |                     f1 tcall.c:11
            |                     f1 tcall.c:10
            |                     main tcall.c:18
            |                     main tcall.c:18
            |                     main tcall.c:17
            |                     main tcall.c:17
            |                     f1 tcall.c:13
            |                     f1 tcall.c:13
            |                     f2 tcall.c:7
            |                     f2 tcall.c:5
            |                     f1 tcall.c:12

The default output is unchanged.

This is only implemented in perf report, no change to record or anywhere
else.

This adds the basic code to report:

- add a new "branch" option to the -g option parser to enable this mode
- when the flag is set include the LBR into the callstack in machine.c.

The rest of the history code is unchanged and doesn't know the
difference between LBR entry and normal call entry.

- detect overlaps with the callchain
- remove small loop duplicates in the LBR

Current limitations:

- The LBR flags (mispredict etc.) are not shown in the history
and LBR entries have no special marker.
- It would be nice if annotate marked the LBR entries somehow
(e.g. with arrows)

v2: Various fixes.
v3: Merge further patches into this one. Fix white space.
v4: Improve manpage. Address review feedback.
v5: Rename functions. Better error message without -g. Fix crash without
    -b.
v6: Rebase
v7: Rebase. Use NO_ENTRY in memset.
v8: Port to latest tip. Move add_callchain_ip to separate
    patch. Skip initial entries in callchain. Minor cleanups.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1415844328-4884-3-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-12-01 20:00:31 -03:00

298 lines
7.4 KiB
C

#ifndef __PERF_SYMBOL
#define __PERF_SYMBOL 1
#include <linux/types.h>
#include <stdbool.h>
#include <stdint.h>
#include "map.h"
#include "../perf.h"
#include <linux/list.h>
#include <linux/rbtree.h>
#include <stdio.h>
#include <byteswap.h>
#include <libgen.h>
#include "build-id.h"
#include "event.h"
#include "util.h"
#ifdef HAVE_LIBELF_SUPPORT
#include <libelf.h>
#include <gelf.h>
#endif
#include <elf.h>
#include "dso.h"
/*
* libelf 0.8.x and earlier do not support ELF_C_READ_MMAP;
* for newer versions we can use mmap to reduce memory usage:
*/
#ifdef HAVE_LIBELF_MMAP_SUPPORT
# define PERF_ELF_C_READ_MMAP ELF_C_READ_MMAP
#else
# define PERF_ELF_C_READ_MMAP ELF_C_READ
#endif
#ifdef HAVE_LIBELF_SUPPORT
extern Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
GElf_Shdr *shp, const char *name, size_t *idx);
#endif
#ifndef DMGL_PARAMS
#define DMGL_NO_OPTS 0 /* For readability... */
#define DMGL_PARAMS (1 << 0) /* Include function args */
#define DMGL_ANSI (1 << 1) /* Include const, volatile, etc */
#endif
/** struct symbol - symtab entry
*
* @ignore - resolvable but tools ignore it (e.g. idle routines)
*/
struct symbol {
struct rb_node rb_node;
u64 start;
u64 end;
u16 namelen;
u8 binding;
bool ignore;
char name[0];
};
void symbol__delete(struct symbol *sym);
void symbols__delete(struct rb_root *symbols);
/* symbols__for_each_entry - iterate over symbols (rb_root)
*
* @symbols: the rb_root of symbols
* @pos: the 'struct symbol *' to use as a loop cursor
* @nd: the 'struct rb_node *' to use as a temporary storage
*/
#define symbols__for_each_entry(symbols, pos, nd) \
for (nd = rb_first(symbols); \
nd && (pos = rb_entry(nd, struct symbol, rb_node)); \
nd = rb_next(nd))
static inline size_t symbol__size(const struct symbol *sym)
{
return sym->end - sym->start;
}
struct strlist;
struct symbol_conf {
unsigned short priv_size;
unsigned short nr_events;
bool try_vmlinux_path,
ignore_vmlinux,
ignore_vmlinux_buildid,
show_kernel_path,
use_modules,
sort_by_name,
show_nr_samples,
show_total_period,
use_callchain,
cumulate_callchain,
exclude_other,
show_cpu_utilization,
initialized,
kptr_restrict,
annotate_asm_raw,
annotate_src,
event_group,
demangle,
demangle_kernel,
filter_relative,
show_hist_headers,
branch_callstack;
const char *vmlinux_name,
*kallsyms_name,
*source_prefix,
*field_sep;
const char *default_guest_vmlinux_name,
*default_guest_kallsyms,
*default_guest_modules;
const char *guestmount;
const char *dso_list_str,
*comm_list_str,
*sym_list_str,
*col_width_list_str;
struct strlist *dso_list,
*comm_list,
*sym_list,
*dso_from_list,
*dso_to_list,
*sym_from_list,
*sym_to_list;
const char *symfs;
};
extern struct symbol_conf symbol_conf;
static inline int __symbol__join_symfs(char *bf, size_t size, const char *path)
{
return path__join(bf, size, symbol_conf.symfs, path);
}
#define symbol__join_symfs(bf, path) __symbol__join_symfs(bf, sizeof(bf), path)
extern int vmlinux_path__nr_entries;
extern char **vmlinux_path;
static inline void *symbol__priv(struct symbol *sym)
{
return ((void *)sym) - symbol_conf.priv_size;
}
struct ref_reloc_sym {
const char *name;
u64 addr;
u64 unrelocated_addr;
};
struct map_symbol {
struct map *map;
struct symbol *sym;
bool unfolded;
bool has_children;
};
struct addr_map_symbol {
struct map *map;
struct symbol *sym;
u64 addr;
u64 al_addr;
};
struct branch_info {
struct addr_map_symbol from;
struct addr_map_symbol to;
struct branch_flags flags;
};
struct mem_info {
struct addr_map_symbol iaddr;
struct addr_map_symbol daddr;
union perf_mem_data_src data_src;
};
struct addr_location {
struct machine *machine;
struct thread *thread;
struct map *map;
struct symbol *sym;
u64 addr;
char level;
u8 filtered;
u8 cpumode;
s32 cpu;
};
struct symsrc {
char *name;
int fd;
enum dso_binary_type type;
#ifdef HAVE_LIBELF_SUPPORT
Elf *elf;
GElf_Ehdr ehdr;
Elf_Scn *opdsec;
size_t opdidx;
GElf_Shdr opdshdr;
Elf_Scn *symtab;
GElf_Shdr symshdr;
Elf_Scn *dynsym;
size_t dynsym_idx;
GElf_Shdr dynshdr;
bool adjust_symbols;
bool is_64_bit;
#endif
};
void symsrc__destroy(struct symsrc *ss);
int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
enum dso_binary_type type);
bool symsrc__has_symtab(struct symsrc *ss);
bool symsrc__possibly_runtime(struct symsrc *ss);
int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter);
int dso__load_vmlinux(struct dso *dso, struct map *map,
const char *vmlinux, bool vmlinux_allocated,
symbol_filter_t filter);
int dso__load_vmlinux_path(struct dso *dso, struct map *map,
symbol_filter_t filter);
int dso__load_kallsyms(struct dso *dso, const char *filename, struct map *map,
symbol_filter_t filter);
struct symbol *dso__find_symbol(struct dso *dso, enum map_type type,
u64 addr);
struct symbol *dso__find_symbol_by_name(struct dso *dso, enum map_type type,
const char *name);
struct symbol *dso__first_symbol(struct dso *dso, enum map_type type);
struct symbol *dso__next_symbol(struct symbol *sym);
enum dso_type dso__type_fd(int fd);
int filename__read_build_id(const char *filename, void *bf, size_t size);
int sysfs__read_build_id(const char *filename, void *bf, size_t size);
int modules__parse(const char *filename, void *arg,
int (*process_module)(void *arg, const char *name,
u64 start));
int filename__read_debuglink(const char *filename, char *debuglink,
size_t size);
struct perf_session_env;
int symbol__init(struct perf_session_env *env);
void symbol__exit(void);
void symbol__elf_init(void);
struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name);
size_t symbol__fprintf_symname_offs(const struct symbol *sym,
const struct addr_location *al, FILE *fp);
size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp);
size_t symbol__fprintf(struct symbol *sym, FILE *fp);
bool symbol_type__is_a(char symbol_type, enum map_type map_type);
bool symbol__restricted_filename(const char *filename,
const char *restricted_filename);
bool symbol__is_idle(struct symbol *sym);
int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
struct symsrc *runtime_ss, symbol_filter_t filter,
int kmodule);
int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss,
struct map *map, symbol_filter_t filter);
void symbols__insert(struct rb_root *symbols, struct symbol *sym);
void symbols__fixup_duplicate(struct rb_root *symbols);
void symbols__fixup_end(struct rb_root *symbols);
void __map_groups__fixup_end(struct map_groups *mg, enum map_type type);
typedef int (*mapfn_t)(u64 start, u64 len, u64 pgoff, void *data);
int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
bool *is_64_bit);
#define PERF_KCORE_EXTRACT "/tmp/perf-kcore-XXXXXX"
struct kcore_extract {
char *kcore_filename;
u64 addr;
u64 offs;
u64 len;
char extract_filename[sizeof(PERF_KCORE_EXTRACT)];
int fd;
};
int kcore_extract__create(struct kcore_extract *kce);
void kcore_extract__delete(struct kcore_extract *kce);
int kcore_copy(const char *from_dir, const char *to_dir);
int compare_proc_modules(const char *from, const char *to);
int setup_list(struct strlist **list, const char *list_str,
const char *list_name);
#endif /* __PERF_SYMBOL */