lkml.org 
[lkml]   [2018]   [Mar]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 23/54] perf mmap: Store mmap scope in struct perf_mmap()
Date
From: Kan Liang <kan.liang@linux.intel.com>

There is too much boilerplate in the perf_mmap__read*() interfaces.

The 'start' and 'end' variables should be stored in struct perf_mmap at
initialization. They will be used later.

The old 'startp' and 'endp' pointers are used by perf_mmap__read_event()
now. They cannot be removed. So the old 'startp/endp' and new
'md->start/md->end' will exist simultaneously now. The old one will be
removed later.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Suggested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1520350567-80082-2-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/mmap.c | 12 ++++++++----
tools/perf/util/mmap.h | 2 ++
2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
index 4f27c464ce0b..09acaf7392bb 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -250,13 +250,15 @@ int perf_mmap__read_init(struct perf_mmap *md, bool overwrite,

*startp = overwrite ? head : old;
*endp = overwrite ? old : head;
+ md->start = md->overwrite ? head : old;
+ md->end = md->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) {
+ if (!md->overwrite) {
WARN_ONCE(1, "failed to keep up with mmap data. (warn only once)\n");

md->prev = head;
@@ -268,8 +270,10 @@ 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 71137977af28..9359e934ab14 100644
--- a/tools/perf/util/mmap.h
+++ b/tools/perf/util/mmap.h
@@ -20,6 +20,8 @@ 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);
--
2.14.3
\
 
 \ /
  Last update: 2018-03-08 20:52    [W:0.135 / U:41.652 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site