lkml.org 
[lkml]   [2013]   [Nov]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCHv3 6/7] perf record: Use perf_data_file__write for output file
On Thu, Nov 28, 2013 at 12:03:44PM -0200, Arnaldo Carvalho de Melo wrote:
> Em Thu, Nov 28, 2013 at 11:30:18AM +0100, Jiri Olsa escreveu:
> > Changing the file output code to use the newly
> > added perf_data_file__write interface.
> >
> > No functional change intended.
>
> But there is one, if we fail the pr_err() will not be called, will some
> warning be emitter later on?

ouch right, I missed that one... attached v3 ;-)

>
> If so, we should make it clear in the changelog. Lemme check by looking
> at that code...

I think it's better we dont change the functionality,
just factor the code..

>
> There are several places where the return of this function is propagated
> and handled with relevant error messages, but at least one, the most
> important, doesn't, i.e. this would be the only message the user would
> receive, can you verify that?

AFAICS they print out high(er) level errors, like for sythesizing
events:
pr_err("Couldn't record guest kernel [%d]'s reference"
" relocation symbol.\n", machine->pid);

I think we want that write failure message as well

thanks,
jirka


---
Changing the file output code to use the newly
added perf_data_file__write interface.

No functional change intended.

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/builtin-record.c | 23 +++++++++--------------
1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index d93e2ee..2402eff 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -76,24 +76,19 @@ struct perf_record {
long samples;
};

-static int perf_record__write(struct perf_record *rec, void *buf, size_t size)
+static ssize_t perf_record__write(struct perf_record *rec,
+ void *buf, size_t size)
{
- struct perf_data_file *file = &rec->file;
-
- while (size) {
- ssize_t ret = write(file->fd, buf, size);
-
- if (ret < 0) {
- pr_err("failed to write perf data, error: %m\n");
- return -1;
- }
-
- size -= ret;
- buf += ret;
+ struct perf_session *session = rec->session;
+ ssize_t ret;

- rec->bytes_written += ret;
+ ret = perf_data_file__write(session->file, buf, size);
+ if (ret < 0) {
+ pr_err("failed to write perf data, error: %m\n");
+ return -1;
}

+ rec->bytes_written += ret;
return 0;
}

--
1.8.3.1


\
 
 \ /
  Last update: 2013-11-28 16:41    [W:0.282 / U:0.288 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site