UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity

perf tools: Replace automatic const char[] variables by statics 

An automatic const char[] variable gets initialized at runtime, just
like any other automatic variable. For long strings, that uses a lot of
stack and wastes time building the string; e.g. for the "No %s
allocation events..." case one has:

  444516:       48 b8 4e 6f 20 25 73 20 61 6c   movabs $0x6c61207325206f4e,%rax # "No %s al"
  ...
  444674:       48 89 45 80                     mov    %rax,-0x80(%rbp)
  444678:       48 b8 6c 6f 63 61 74 69 6f 6e   movabs $0x6e6f697461636f6c,%rax # "location"
  444682:       48 89 45 88                     mov    %rax,-0x78(%rbp)
  444686:       48 b8 20 65 76 65 6e 74 73 20   movabs $0x2073746e65766520,%rax # " events "
  444690:       66 44 89 55 c4                  mov    %r10w,-0x3c(%rbp)
  444695:       48 89 45 90                     mov    %rax,-0x70(%rbp)
  444699:       48 b8 66 6f 75 6e 64 2e 20 20   movabs $0x20202e646e756f66,%rax

Make them all static so that the compiler just references objects in .rodata.

Committer testing:

Ok, using dwarves's codiff tool:

    $ codiff --functions /tmp/perf.before ~/bin/perf
  builtin-sched.c:
    cmd_sched                 |  -48
   1 function changed, 48 bytes removed, diff: -48

  builtin-report.c:
    cmd_report                |  -32
   1 function changed, 32 bytes removed, diff: -32

  builtin-kmem.c:
    cmd_kmem                  |  -64
    build_alloc_func_list     |  -50
   2 functions changed, 114 bytes removed, diff: -114

  builtin-c2c.c:
    perf_c2c__report          | -390
   1 function changed, 390 bytes removed, diff: -390

  ui/browsers/header.c:
    tui__header_window        | -104
   1 function changed, 104 bytes removed, diff: -104

  /home/acme/bin/perf:
   9 functions changed, 688 bytes removed, diff: -688

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20181102230624.20064-1-linux@rasmusvillemoes.dk
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Rasmus Villemoes 2018-11-03 00:06:23 +01:00 committed by Arnaldo Carvalho de Melo
parent ad07c8ceb6
commit 49b8e2bece
6 changed files with 11 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
tools/perf/builtin-c2c.c
View File

@ -2343,7 +2343,7 @@ static int perf_c2c__browse_cacheline(struct hist_entry *he)
struct c2c_cacheline_browser *cl_browser;
struct hist_browser *browser;
int key = -1;
const char help[] =
static const char help[] =
" ENTER Toggle callchains (if present) \n"
" n Toggle Node details info \n"
" s Toggle full length of symbol and source line columns \n"
@ -2424,7 +2424,7 @@ static int perf_c2c__hists_browse(struct hists *hists)
{
struct hist_browser *browser;
int key = -1;
const char help[] =
static const char help[] =
" d Display cacheline details \n"
" ENTER Toggle callchains (if present) \n"
" q Quit \n";

4
tools/perf/builtin-kmem.c
View File

@ -334,7 +334,7 @@ static int build_alloc_func_list(void)
struct alloc_func *func;
struct machine *machine = &kmem_session->machines.host;
regex_t alloc_func_regex;
const char pattern[] = "^_?_?(alloc|get_free|get_zeroed)_pages?";
static const char pattern[] = "^_?_?(alloc|get_free|get_zeroed)_pages?";
ret = regcomp(&alloc_func_regex, pattern, REG_EXTENDED);
if (ret) {
@ -1924,7 +1924,7 @@ int cmd_kmem(int argc, const char **argv)
NULL
};
struct perf_session *session;
const char errmsg[] = "No %s allocation events found. Have you run 'perf kmem record --%s'?\n";
static const char errmsg[] = "No %s allocation events found. Have you run 'perf kmem record --%s'?\n";
int ret = perf_config(kmem_config, NULL);
if (ret)

6
tools/perf/builtin-report.c
View File

@ -956,9 +956,9 @@ int cmd_report(int argc, const char **argv)
int branch_mode = -1;
bool branch_call_mode = false;
#define CALLCHAIN_DEFAULT_OPT "graph,0.5,caller,function,percent"
const char report_callchain_help[] = "Display call graph (stack chain/backtrace):\n\n"
CALLCHAIN_REPORT_HELP
"\n\t\t\t\tDefault: " CALLCHAIN_DEFAULT_OPT;
static const char report_callchain_help[] = "Display call graph (stack chain/backtrace):\n\n"
CALLCHAIN_REPORT_HELP
"\n\t\t\t\tDefault: " CALLCHAIN_DEFAULT_OPT;
char callchain_default_opt[] = CALLCHAIN_DEFAULT_OPT;
const char * const report_usage[] = {
"perf report [<options>]",

2
tools/perf/builtin-sched.c
View File

@ -3336,7 +3336,7 @@ static int __cmd_record(int argc, const char **argv)
int cmd_sched(int argc, const char **argv)
{
const char default_sort_order[] = "avg, max, switch, runtime";
static const char default_sort_order[] = "avg, max, switch, runtime";
struct perf_sched sched = {
.tool = {
.sample = perf_sched__process_tracepoint_sample,

2
tools/perf/ui/browsers/header.c
View File

@ -35,7 +35,7 @@ static int list_menu__run(struct ui_browser *menu)
{
int key;
unsigned long offset;
const char help[] =
static const char help[] =
"h/?/F1 Show this window\n"
"UP/DOWN/PGUP\n"
"PGDN/SPACE\n"

4
tools/perf/ui/browsers/hists.c
View File

@ -2748,7 +2748,7 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
"S Zoom into current Processor Socket\n" \
/* help messages are sorted by lexical order of the hotkey */
const char report_help[] = HIST_BROWSER_HELP_COMMON
static const char report_help[] = HIST_BROWSER_HELP_COMMON
"i Show header information\n"
"P Print histograms to perf.hist.N\n"
"r Run available scripts\n"
@ -2756,7 +2756,7 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
"t Zoom into current Thread\n"
"V Verbose (DSO names in callchains, etc)\n"
"/ Filter symbol by name";
const char top_help[] = HIST_BROWSER_HELP_COMMON
static const char top_help[] = HIST_BROWSER_HELP_COMMON
"P Print histograms to perf.hist.N\n"
"t Zoom into current Thread\n"
"V Verbose (DSO names in callchains, etc)\n"