Messages in this thread Patch in this message | | | From | Don Zickus <> | Subject | [PATCH 5/6] perf: Update sort to handle MAP_SHARED bits | Date | Mon, 24 Mar 2014 15:34:35 -0400 |
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Remove some of the false positives when sorting by utilizing the MAP_SHARED bit.
This helps deal with the COW cases where a virtual address is modified but is mapped to a read-only shared library area because the perf tool doesn't understand COW faults.
Using the MAP_SHARED bit tells the tool in this example the memory is private and will not cause contention with other processes accessing the same shared library area.
Signed-off-by: Don Zickus <dzickus@redhat.com> --- tools/perf/util/sort.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c index e016fc1..be675f4 100644 --- a/tools/perf/util/sort.c +++ b/tools/perf/util/sort.c @@ -1,3 +1,4 @@ +#include <sys/mman.h> #include "sort.h" #include "hist.h" #include "comm.h" @@ -1001,7 +1002,8 @@ sort__physid_daddr_cmp(struct hist_entry *left, struct hist_entry *right) * assumed to be unity mapped. Sort those on address then pid. */ - if (l_map->maj || l_map->min || l_map->ino || l_map->ino_generation) { + if ((l_map->flags & MAP_SHARED) && + (l_map->maj || l_map->min || l_map->ino || l_map->ino_generation)) { /* mmapped areas */ if (l_map->maj > r_map->maj) return -1; -- 1.7.11.7
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