On 3/5/2018 3:20 PM, Arnaldo Carvalho de Melo wrote:
Em Mon, Mar 05, 2018 at 02:10:53PM -0500, [email protected] escreveu:
From: Kan Liang <[email protected]>
There are too many boilerplates for the perf_mmap__read*() interfaces.
Some of the data (e.g. 'start', 'end', 'overwrite') should be stored in
struct perf_mmap at initialization. They will be used later.
No functional change.
Signed-off-by: Kan Liang <[email protected]>
---
tools/perf/util/mmap.c | 11 ++++++++---
tools/perf/util/mmap.h | 3 +++
2 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
index 4f27c46..642b479 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -250,11 +250,14 @@ int perf_mmap__read_init(struct perf_mmap *md, bool
overwrite,
*startp = overwrite ? head : old;
*endp = overwrite ? old : head;
Why did you keep the above and haven't removed the startp/endp args?
The startp/endp are used by perf_mmap__read_event().
I don't want to make all the changes in a single patch. I think it's
hard to review.
So I modified the interface one by one.
Only changing one interface will break the usage.
So the old 'startp/endp' and new 'md->start/md->end' will exist
simultaneously in the first few patches. They have the same value.
Patch 1,3,4 add the new 'md->start/md->end' for the three interfaces.
Patch 2 uses the new 'md->start/md->end' for perf record.
Patch 5,6,7 remove the old 'startp/endp' for other perf tools/test and
refine the interfaces.
Thanks,
Kan
to
ease the conversion somehow? I'll look at the other patches, but I think
we should change the function signature here and in the callers all at
once.
Sometimes this is ok, and probably this is one case.
- Arnaldo
+ md->overwrite = overwrite;
+ md->start = overwrite ? head : old;
+ md->end = overwrite ? old : head;
- if (*startp == *endp)
+ if (md->start == md->end)
return -EAGAIN;
- size = *endp - *startp;
+ size = md->end - md->start;
if (size > (unsigned long)(md->mask) + 1) {
if (!overwrite) {
WARN_ONCE(1, "failed to keep up with mmap data. (warn only
once)\n");
@@ -268,8 +271,10 @@ int perf_mmap__read_init(struct perf_mmap *md, bool
overwrite,
* Backward ring buffer is full. We still have a chance to read
* most of data from it.
*/
- if (overwrite_rb_find_range(data, md->mask, head, startp, endp))
+ if (overwrite_rb_find_range(data, md->mask, head, &md->start,
&md->end))
return -EINVAL;
+ *startp = md->start;
+ *endp = md->end;
}
return 0;
diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h
index ec7d3a24..9359e93 100644
--- a/tools/perf/util/mmap.h
+++ b/tools/perf/util/mmap.h
@@ -20,6 +20,9 @@ struct perf_mmap {
int fd;
refcount_t refcnt;
u64 prev;
+ u64 start;
+ u64 end;
+ bool overwrite;
struct auxtrace_mmap auxtrace_mmap;
char event_copy[PERF_SAMPLE_MAX_SIZE] __aligned(8);
};
--
2.4.11
