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author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2009-05-26 19:20:57 -0300 |
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committer | Ingo Molnar <mingo@elte.hu> | 2009-05-27 09:10:35 +0200 |
commit | d8d1656ee15d3085e0085a87e70f9093a0a102c5 (patch) | |
tree | e16d2f8db17e2c805d4c5a1bd3b2c6c435ed1fd4 /Documentation | |
parent | 3a4b8cc70b7473a0b9f26f5b4ddc6579b5e214be (diff) | |
download | op-kernel-dev-d8d1656ee15d3085e0085a87e70f9093a0a102c5.zip op-kernel-dev-d8d1656ee15d3085e0085a87e70f9093a0a102c5.tar.gz |
perf report: Use hex2long instead of sscanf
Before:
[acme@emilia ~]$ perf record -o perf_report.perf perf stat perf report > /dev/null
Performance counter stats for 'perf':
245.414985 task clock ticks (msecs)
6 context switches (events)
6 CPU migrations (events)
2108 pagefaults (events)
37493013 CPU cycles (events) (scaled from 67.04%)
13576789 instructions (events) (scaled from 66.76%)
57931 cache references (events) (scaled from 21.96%)
12263 cache misses (events) (scaled from 21.98%)
Wall-clock time elapsed: 246.575587 msecs
[acme@emilia ~]$ perf report -i perf_report.perf | head
12.15 perf [.] 0x000000000005432a /lib64/libc-2.5.so: _IO_vfscanf_internal
9.38 perf [k] 0xffffffff8101b1d2 intel_pmu_enable_all
8.53 perf [.] 0x00000000000056b8 /home/acme/git/linux-2.6-tip/Documentation/perf_counter/perf: dso__insert_symbol
6.61 perf [.] 0x00000000000057cb /home/acme/git/linux-2.6-tip/Documentation/perf_counter/perf: dso__find_symbol
5.33 perf [k] 0xffffffff811ce082 number
4.69 perf [.] 0x0000000000034829 /lib64/libc-2.5.so: ____strtoull_l_internal
4.48 perf [.] 0x0000000000006505 /home/acme/git/linux-2.6-tip/Documentation/perf_counter/perf: thread__symbol_incnew
3.41 perf [.] 0x000000000000fce6 /home/acme/git/linux-2.6-tip/Documentation/perf_counter/perf: rb_insert_color
3.20 perf [k] 0xffffffff811cfc01 vsnprintf
2.99 perf [k] 0xffffffff811ce5e8 format_decode
After:
[acme@emilia ~]$ perf record -o perf_report.perf perf stat perf report > /dev/null
Performance counter stats for 'perf':
218.186805 task clock ticks (msecs)
4 context switches (events)
7 CPU migrations (events)
2133 pagefaults (events)
32735365 CPU cycles (events) (scaled from 67.04%)
11952309 instructions (events) (scaled from 66.26%)
50314 cache references (events) (scaled from 21.96%)
13228 cache misses (events) (scaled from 21.98%)
Wall-clock time elapsed: 218.810451 msecs
[acme@emilia ~]$ perf report -i perf_report.perf | head
10.68 perf [.] 0x000000000000578d /home/acme/git/linux-2.6-tip/Documentation/perf_counter/perf: dso__find_symbol
9.62 perf [.] 0x00000000000065f7 /home/acme/git/linux-2.6-tip/Documentation/perf_counter/perf: thread__symbol_incnew
9.40 perf [.] 0x00000000000056b4 /home/acme/git/linux-2.6-tip/Documentation/perf_counter/perf: dso__insert_symbol
9.19 perf [k] 0xffffffff8101b1d2 intel_pmu_enable_all
5.13 perf [.] 0x0000000000005ec7 /home/acme/git/linux-2.6-tip/Documentation/perf_counter/perf: hex2long
4.49 perf [k] 0xffffffff81083808 kallsyms_expand_symbol
3.85 perf [k] 0xffffffff811ce2c1 number
3.63 perf [.] 0x0000000000005e81 /home/acme/git/linux-2.6-tip/Documentation/perf_counter/perf: hex
2.99 perf [.] 0x000000000000fd5b /home/acme/git/linux-2.6-tip/Documentation/perf_counter/perf: rb_insert_color
2.99 perf [k] 0xffffffff811cf251 string
[acme@emilia ~]$
[ Impact: optimization ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Kacur <jkacur@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20090526222057.GI4424@ghostprotocols.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/perf_counter/builtin-report.c | 63 |
1 files changed, 50 insertions, 13 deletions
diff --git a/Documentation/perf_counter/builtin-report.c b/Documentation/perf_counter/builtin-report.c index a4c6ffa..c517483 100644 --- a/Documentation/perf_counter/builtin-report.c +++ b/Documentation/perf_counter/builtin-report.c @@ -348,6 +348,39 @@ void dsos__fprintf(FILE *fp) dso__fprintf(pos, fp); } +static int hex(char ch) +{ + if ((ch >= '0') && (ch <= '9')) + return ch - '0'; + if ((ch >= 'a') && (ch <= 'f')) + return ch - 'a' + 10; + if ((ch >= 'A') && (ch <= 'F')) + return ch - 'A' + 10; + return -1; +} + +/* + * While we find nice hex chars, build a long_val. + * Return number of chars processed. + */ +int hex2long(char *ptr, unsigned long *long_val) +{ + const char *p = ptr; + *long_val = 0; + + while (*p) { + const int hex_val = hex(*p); + + if (hex_val < 0) + break; + + *long_val = (*long_val << 4) | hex_val; + p++; + } + + return p - ptr; +} + static int load_kallsyms(void) { kernel_dso = dso__new("[kernel]"); @@ -363,26 +396,30 @@ static int load_kallsyms(void) size_t n; while (!feof(file)) { - unsigned long long start; - char c, symbf[4096]; - - if (getline(&line, &n, file) < 0) + unsigned long start; + int line_len = getline(&line, &n, file); + if (line_len < 0) break; if (!line) goto out_delete_dso; - if (sscanf(line, "%llx %c %s", &start, &c, symbf) == 3) { - /* - * Well fix up the end later, when we have all sorted. - */ - struct symbol *sym = symbol__new(start, 0xdead, symbf); + line[--line_len] = '\0'; /* \n */ + + int len = hex2long(line, &start); + + len += 3; /* ' t ' */ + if (len >= line_len) + continue; + /* + * Well fix up the end later, when we have all sorted. + */ + struct symbol *sym = symbol__new(start, 0xdead, line + len); - if (sym == NULL) - goto out_delete_dso; + if (sym == NULL) + goto out_delete_dso; - dso__insert_symbol(kernel_dso, sym); - } + dso__insert_symbol(kernel_dso, sym); } /* |