Messages in this thread | | | Date | Sat, 16 May 2015 21:10:59 +0900 | From | Masami Hiramatsu <> | Subject | Re: Re: [PATCH tip/perf/core] perf probe: Load map before glob matching |
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On 2015/05/16 5:07, Arnaldo Carvalho de Melo wrote: > Em Sat, May 16, 2015 at 12:15:45AM +0900, Masami Hiramatsu escreveu: >> On 2015/05/15 21:14, Wang Nan wrote: >>> Commit 4c859351226c920b227fec040a3b447f0d482af3 ("perf probe: Support >>> glob wildcards for function name") introduces a problem: >>> >>> # /root/perf probe kmem_cache_free >>> Failed to find symbol kmem_cache_free in kernel >>> Error: Failed to add events. >>> >>> The reason is the replacement of map__for_each_symbol_by_name() (by >>> map__for_each_symbol()). Although their names are similay, >>> map__for_each_symbol doesn't call map__load() and dso__sort_by_name() >>> before searching. The missing of map__load() causes this problem >>> because it search symbol before load dso map. >> >> Oops, yes. But I think we'd better fix map__for_each_symbol() to call >> map__load() if the map is not loaded, doesn't it? > > Well, that is something for a follow up patch, I'm applying his patch as > it fixes a problem and is trivially correct.
OK, then I'm OK for this patch.
Thank you,
> > - Arnaldo > >> Thank you, >> >>> >>> This patch ensures map__load() is called before using >>> map__for_each_symbol(). >>> >>> After this patch: >>> >>> # /root/perf probe kmem_cache_free >>> Added new event: >>> probe:kmem_cache_free (on kmem_cache_free%return) >>> >>> You can now use it in all perf tools, such as: >>> >>> perf record -e probe:kmem_cache_free -aR sleep 1 >>> >>> Signed-off-by: Wang Nan <wangnan0@huawei.com> >>> --- >>> tools/perf/util/probe-event.c | 3 +++ >>> 1 file changed, 3 insertions(+) >>> >>> diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c >>> index 2399dc4..1faa1e6 100644 >>> --- a/tools/perf/util/probe-event.c >>> +++ b/tools/perf/util/probe-event.c >>> @@ -2499,6 +2499,9 @@ static int find_probe_functions(struct map *map, char *name) >>> struct symbol *sym; >>> struct rb_node *tmp; >>> >>> + if (map__load(map, NULL) < 0) >>> + return 0; >>> + >>> map__for_each_symbol(map, sym, tmp) { >>> if (strglobmatch(sym->name, name)) >>> found++; >>> >> -- Masami HIRAMATSU Linux Technology Research Center, System Productivity Research Dept. Center for Technology Innovation - Systems Engineering Hitachi, Ltd., Research & Development Group E-mail: masami.hiramatsu.pt@hitachi.com
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