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| author | Kan Liang <kan.liang@intel.com> | 2018-01-18 13:26:19 -0800 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2018-02-15 09:52:22 -0300 |
| commit | 8872481bd04850b19e053dc579de5a11b83b16fc (patch) | |
| tree | 1ab57d0e91aca3240df33aa3c2ac528df68804f2 | |
| parent | f92c8cbe597a5a2ccec702dff824f3fe0f3623eb (diff) | |
| download | linux-stable-8872481bd04850b19e053dc579de5a11b83b16fc.tar.gz linux-stable-8872481bd04850b19e053dc579de5a11b83b16fc.tar.bz2 linux-stable-8872481bd04850b19e053dc579de5a11b83b16fc.zip | |
perf mmap: Introduce perf_mmap__read_init()
The new function perf_mmap__read_init() is factored out from
perf_mmap__push().
It is to calculate the 'start' and 'end' of the available data in
ringbuffer.
No functional change.
Signed-off-by: Kan Liang <kan.liang@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1516310792-208685-5-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/util/mmap.c | 37 | ||||
| -rw-r--r-- | tools/perf/util/mmap.h | 2 |
2 files changed, 29 insertions, 10 deletions
diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c index fbbbe87f0308..c19a4e640e8e 100644 --- a/tools/perf/util/mmap.c +++ b/tools/perf/util/mmap.c @@ -267,24 +267,24 @@ static int overwrite_rb_find_range(void *buf, int mask, u64 head, u64 *start, u6 return -1; } -int perf_mmap__push(struct perf_mmap *md, bool overwrite, - void *to, int push(void *to, void *buf, size_t size)) +/* + * Report the start and end of the available data in ringbuffer + */ +int perf_mmap__read_init(struct perf_mmap *md, bool overwrite, + u64 *startp, u64 *endp) { u64 head = perf_mmap__read_head(md); u64 old = md->prev; - u64 end, start; unsigned char *data = md->base + page_size; unsigned long size; - void *buf; - int rc = 0; - start = overwrite ? head : old; - end = overwrite ? old : head; + *startp = overwrite ? head : old; + *endp = overwrite ? old : head; - if (start == end) + if (*startp == *endp) return 0; - size = end - start; + size = *endp - *startp; if (size > (unsigned long)(md->mask) + 1) { if (!overwrite) { WARN_ONCE(1, "failed to keep up with mmap data. (warn only once)\n"); @@ -298,10 +298,27 @@ int perf_mmap__push(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, &start, &end)) + if (overwrite_rb_find_range(data, md->mask, head, startp, endp)) return -1; } + return 1; +} + +int perf_mmap__push(struct perf_mmap *md, bool overwrite, + void *to, int push(void *to, void *buf, size_t size)) +{ + u64 head = perf_mmap__read_head(md); + u64 end, start; + unsigned char *data = md->base + page_size; + unsigned long size; + void *buf; + int rc = 0; + + rc = perf_mmap__read_init(md, overwrite, &start, &end); + if (rc < 1) + return rc; + size = end - start; if ((start & md->mask) + size != (end & md->mask)) { diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h index e43d7b55a55f..9ab2b48df65b 100644 --- a/tools/perf/util/mmap.h +++ b/tools/perf/util/mmap.h @@ -94,4 +94,6 @@ int perf_mmap__push(struct perf_mmap *md, bool backward, size_t perf_mmap__mmap_len(struct perf_mmap *map); +int perf_mmap__read_init(struct perf_mmap *md, bool overwrite, + u64 *startp, u64 *endp); #endif /*__PERF_MMAP_H */ |