Commit-ID:  c52686f9f888d23ca72f1309e86af8e91d075697
Gitweb:     http://git.kernel.org/tip/c52686f9f888d23ca72f1309e86af8e91d075697
Author:     Namhyung Kim <[email protected]>
AuthorDate: Thu, 29 Jan 2015 17:02:01 -0300
Committer:  Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Thu, 29 Jan 2015 17:02:01 -0300

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 <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: 
http://lkml.kernel.org/r/[email protected]
[ Fixed it up when cherry picking it from the multi threaded patchkit ]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
 tools/perf/util/dso.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 45be944..c2f7d3b 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;
 
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