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authorNamhyung Kim <namhyung@kernel.org>2015-01-29 17:02:01 -0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2015-01-29 17:02:01 -0300
commitc52686f9f888d23ca72f1309e86af8e91d075697 (patch)
tree7098b1f13486d538e522191c577c632d3c6cb37e
parent42aa276f40730211383e9a9923416f1fb9841d68 (diff)
perf symbols: Convert lseek + read to pread
When dso_cache__read() is called, it reads data from the given offset using lseek + normal read syscall. It can be combined to a single pread syscall. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1422518843-25818-40-git-send-email-namhyung@kernel.org [ Fixed it up when cherry picking it from the multi threaded patchkit ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-rw-r--r--tools/perf/util/dso.c6
1 files changed, 1 insertions, 5 deletions
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 45be944d450..c2f7d3b9096 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -532,12 +532,8 @@ dso_cache__read(struct dso *dso, u64 offset, u8 *data, ssize_t size)
break;
cache_offset = offset & DSO__DATA_CACHE_MASK;
- ret = -EINVAL;
- if (-1 == lseek(dso->data.fd, cache_offset, SEEK_SET))
- break;
-
- ret = read(dso->data.fd, cache->data, DSO__DATA_CACHE_SIZE);
+ ret = pread(dso->data.fd, cache->data, DSO__DATA_CACHE_SIZE, cache_offset);
if (ret <= 0)
break;