[tip:perf/urgent] perf mmap: Add new return value logic for perf_mmap__read_init()
From: tip-bot for Kan Liang
Date: Fri Feb 16 2018 - 04:51:11 EST
Commit-ID: 189f2cc91f9f2efef5d5f4dde43684c01b5f6f2f
Gitweb: https://git.kernel.org/tip/189f2cc91f9f2efef5d5f4dde43684c01b5f6f2f
Author: Kan Liang <kan.liang@xxxxxxxxx>
AuthorDate: Thu, 18 Jan 2018 13:26:20 -0800
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Thu, 15 Feb 2018 09:52:49 -0300
perf mmap: Add new return value logic for perf_mmap__read_init()
Improve the readability by using meaningful enum (-EAGAIN, -EINVAL and
0) to replace the three returning states (0, -1 and 1).
Suggested-by: Wang Nan <wangnan0@xxxxxxxxxx>
Signed-off-by: Kan Liang <kan.liang@xxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1516310792-208685-6-git-send-email-kan.liang@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/mmap.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
index c19a4e6..38fa69d 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -282,7 +282,7 @@ int perf_mmap__read_init(struct perf_mmap *md, bool overwrite,
*endp = overwrite ? old : head;
if (*startp == *endp)
- return 0;
+ return -EAGAIN;
size = *endp - *startp;
if (size > (unsigned long)(md->mask) + 1) {
@@ -291,7 +291,7 @@ int perf_mmap__read_init(struct perf_mmap *md, bool overwrite,
md->prev = head;
perf_mmap__consume(md, overwrite);
- return 0;
+ return -EAGAIN;
}
/*
@@ -299,10 +299,10 @@ int perf_mmap__read_init(struct perf_mmap *md, bool overwrite,
* most of data from it.
*/
if (overwrite_rb_find_range(data, md->mask, head, startp, endp))
- return -1;
+ return -EINVAL;
}
- return 1;
+ return 0;
}
int perf_mmap__push(struct perf_mmap *md, bool overwrite,
@@ -316,8 +316,8 @@ int perf_mmap__push(struct perf_mmap *md, bool overwrite,
int rc = 0;
rc = perf_mmap__read_init(md, overwrite, &start, &end);
- if (rc < 1)
- return rc;
+ if (rc < 0)
+ return (rc == -EAGAIN) ? 0 : -1;
size = end - start;