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perf mmap: Store mmap scope in struct perf_mmap()

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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>
This commit is contained in:
Kan Liang 2018-03-06 10:36:01 -05:00 committed by Arnaldo Carvalho de Melo
parent 2c5f6d876b
commit 4fda3459e3
2 changed files with 10 additions and 4 deletions
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12
tools/perf/util/mmap.c
View File

@ -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;

2
tools/perf/util/mmap.h
View File

@ -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);