From: Jiri Olsa <jolsa@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: Jiri Olsa <jolsa@redhat.com>, Ingo Molnar <mingo@kernel.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Namhyung Kim <namhyung@kernel.org>,
Mike Galbraith <efault@gmx.de>, David Ahern <dsahern@gmail.com>,
Adrian Hunter <adrian.hunter@intel.com>,
Arnaldo Carvalho de Melo <acme@redhat.com>
Subject: [PATCH 3/7] perf tools: Fine tune readn function
Date: Thu, 28 Nov 2013 11:30:15 +0100 [thread overview]
Message-ID: <1385634619-8129-4-git-send-email-jolsa@redhat.com> (raw)
In-Reply-To: <1385634619-8129-1-git-send-email-jolsa@redhat.com>
Added a 'left' variable to make the flow clearer, and added a debug
check for the return value - returning 'n' is more obvious.
Added small comment for readn.
Original-patch-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/util.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 9440481..6ea0b4a 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -6,6 +6,7 @@
#endif
#include <stdio.h>
#include <stdlib.h>
+#include <linux/kernel.h>
/*
* XXX We need to find a better place for these things...
@@ -151,21 +152,26 @@ unsigned long convert_unit(unsigned long value, char *unit)
return value;
}
+/*
+ * Read exactly 'n' bytes or return an error.
+ */
ssize_t readn(int fd, void *buf, size_t n)
{
void *buf_start = buf;
+ size_t left = n;
- while (n) {
- ssize_t ret = read(fd, buf, n);
+ while (left) {
+ ssize_t ret = read(fd, buf, left);
if (ret <= 0)
return ret;
- n -= ret;
- buf += ret;
+ left -= ret;
+ buf += ret;
}
- return buf - buf_start;
+ BUG_ON((size_t)(buf - buf_start) != n);
+ return n;
}
size_t hex_width(u64 v)
--
1.8.3.1
next prev parent reply other threads:[~2013-11-28 10:30 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-28 10:30 [PATCHv2 0/7] perf tools: Add data file write interface Jiri Olsa
2013-11-28 10:30 ` [PATCH 1/7] perf record: Unify data output code into perf_record__write function Jiri Olsa
2013-12-04 15:40 ` [tip:perf/core] " tip-bot for Jiri Olsa
2013-11-28 10:30 ` [PATCH 2/7] perf tools: Use correct return type for readn function Jiri Olsa
2013-12-04 15:40 ` [tip:perf/core] " tip-bot for Jiri Olsa
2013-11-28 10:30 ` Jiri Olsa [this message]
2013-11-28 15:19 ` [PATCH 3/7] perf tools: Fine tune " David Ahern
2013-11-28 15:43 ` [PATCHv3 " Jiri Olsa
2013-11-28 16:03 ` David Ahern
2013-12-04 15:40 ` [tip:perf/core] " tip-bot for Jiri Olsa
2013-11-28 10:30 ` [PATCH 4/7] perf tools: Add writen function Jiri Olsa
2013-12-04 15:40 ` [tip:perf/core] " tip-bot for Jiri Olsa
2013-11-28 10:30 ` [PATCH 5/7] perf tools: Add perf_data_file__write interface Jiri Olsa
2013-12-04 15:40 ` [tip:perf/core] " tip-bot for Jiri Olsa
2013-11-28 10:30 ` [PATCH 6/7] perf record: Use perf_data_file__write for output file Jiri Olsa
2013-11-28 14:03 ` Arnaldo Carvalho de Melo
2013-11-28 15:21 ` [PATCHv3 " Jiri Olsa
2013-11-28 10:30 ` [PATCH 7/7] perf inject: Handle output file via perf_data_file object Jiri Olsa
2013-11-28 14:14 ` Arnaldo Carvalho de Melo
2013-11-28 15:30 ` Jiri Olsa
2013-11-28 10:36 ` [PATCHv2 0/7] perf tools: Add data file write interface Jiri Olsa
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