Error reporting improvement

PATCH In review Adrien BAK 3 participants 3 messages Apr 16, 2014 – Apr 17, 2014 perf events

Share & tools

Adrien BAK

author

2014-04-16 11:11 UTC #0 lore raw

PATCH 1/1 Error reporting improvement

In the current version, when using perf record, if something goes wrong in tools/perf/builtin-record.c:375 session = perf_session__new(file, false, NULL); The error message:
"Not enough memory for reading per file header"
is issued. This error message seems to be outdated and is not very helpful. This patch propose to replace this error message by
"Perf session creation failed"

I believe this issue has been brought to lkml :
https://lkml.org/lkml/2014/2/24/458
although this patch only tackle a (small) part of the issue.

Additionnaly, this patch improves error reporting in tools/perf/util/data.c open_file_write
Currently, if the call to open fails, the user is unaware of it. This patch logs the error, before returning the error code to the caller.

Signed-off-by Adrien BAK <[email protected]>

---

tools/perf/builtin-record.c +1 -1

index eb524f9..8ce62ef 100644
@@ -374,7 +374,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 
     session = perf_session__new(file, false, NULL);
     if (session == NULL) {
-        pr_err("Not enough memory for reading perf file header\n");
+        pr_err("Perf session creation failed.\n");
         return -1;
     }

tools/perf/util/data.c +7 -1

index 1fbcd8b..ff2ced7 100644
@@ -86,10 +86,16 @@ static int open_file_read(struct perf_data_file *file)
 
 static int open_file_write(struct perf_data_file *file)
 {
+    int fd;
     if (check_backup(file))
         return -1;
 
-    return open(file->path, O_CREAT|O_RDWR|O_TRUNC, S_IRUSR|S_IWUSR);
+    fd = open(file->path, O_CREAT|O_RDWR|O_TRUNC, S_IRUSR|S_IWUSR);
+
+    if (fd < 0)
+        pr_err("failed to open %s : %s\n", file->path, strerror(errno));
+
+    return fd;
 }
 
 static int open_file(struct perf_data_file *file)

Will Deacon

2014-04-16 14:26 UTC #1 lore raw

Hi Adrien,

Quoted 13 lines · Adrien BAK

In the current version, when using perf record, if something goes wrong in tools/perf/builtin-record.c:375 session = perf_session__new(file, false, NULL);
The error message:
"Not enough memory for reading per file header"
is issued. This error message seems to be outdated and is not very helpful. This patch propose to replace this error message by
"Perf session creation failed"
I believe this issue has been brought to lkml :
https://lkml.org/lkml/2014/2/24/458
although this patch only tackle a (small) part of the issue.

Quoted 6 lines

Additionnaly, this patch improves error reporting in tools/perf/util/data.c open_file_write
Currently, if the call to open fails, the user is unaware of it. This patch logs the error, before returning the error code to the caller.
Signed-off-by Adrien BAK <[email protected]>

Whilst this patch (admittedly) only solves part of the problem, I think it makes the error I encountered a lot easier to understand.

Thanks,

Reported-by Will Deacon <[email protected]>

Will

Quoted 40 lines

---

tools/perf/builtin-record.c +1 -1

index eb524f9..8ce62ef 100644
@@ -374,7 +374,7 @@ static int __cmd_record(struct record *rec, int 
 argc, const char **argv)
 
      session = perf_session__new(file, false, NULL);
      if (session == NULL) {
-        pr_err("Not enough memory for reading perf file header\n");
+        pr_err("Perf session creation failed.\n");
          return -1;
      }

tools/perf/util/data.c +7 -1

index 1fbcd8b..ff2ced7 100644
@@ -86,10 +86,16 @@ static int open_file_read(struct perf_data_file *file)
 
  static int open_file_write(struct perf_data_file *file)
  {
+    int fd;
      if (check_backup(file))
          return -1;
 
-    return open(file->path, O_CREAT|O_RDWR|O_TRUNC, S_IRUSR|S_IWUSR);
+    fd = open(file->path, O_CREAT|O_RDWR|O_TRUNC, S_IRUSR|S_IWUSR);
+
+    if (fd < 0)
+        pr_err("failed to open %s : %s\n", file->path, strerror(errno));
+
+    return fd;
  }
 
  static int open_file(struct perf_data_file *file)

Jiri Olsa

2014-04-17 09:56 UTC #2 lore raw

Quoted 21 lines · Will Deacon

Hi Adrien,
Quoted 18 lines · Adrien BAK
In the current version, when using perf record, if something goes wrong in tools/perf/builtin-record.c:375 session = perf_session__new(file, false, NULL);
The error message:
"Not enough memory for reading per file header"
is issued. This error message seems to be outdated and is not very helpful. This patch propose to replace this error message by
"Perf session creation failed"
I believe this issue has been brought to lkml :
https://lkml.org/lkml/2014/2/24/458
although this patch only tackle a (small) part of the issue.
Additionnaly, this patch improves error reporting in tools/perf/util/data.c open_file_write
Currently, if the call to open fails, the user is unaware of it. This patch logs the error, before returning the error code to the caller.

Quoted 8 lines

Quoted 1 line
Signed-off-by Adrien BAK <[email protected]>
Whilst this patch (admittedly) only solves part of the problem, I think it makes the error I encountered a lot easier to understand.
Thanks,
Reported-by Will Deacon <[email protected]>

seems ok to me, but the patch is mangled:

[jolsa@krava perf]$ git am /tmp/b
Applying: Error reporting improvement
fatal: corrupt patch at line 7
Patch failed at 0001 Error reporting improvement
The copy of the patch that failed is found in:
/home/jolsa/kernel.org/linux-perf/.git/rebase-apply/patch
When you have resolved this problem, run "git am --resolved". If you prefer to skip this patch, run "git am --skip" instead. To restore the original branch and stop patching, run "git am --abort".

[jolsa@krava perf]$ patch -p3 < /tmp/b1
patching file builtin-record.c
patch: **** malformed patch at line 87: argc, const char **argv)

please check Documentation/email-clients.txt and resend

thanks,
jirka

Quoted 47 lines

Will

Quoted 30 lines

---

tools/perf/builtin-record.c +1 -1

index eb524f9..8ce62ef 100644
@@ -374,7 +374,7 @@ static int __cmd_record(struct record *rec, int 
 argc, const char **argv)
 
      session = perf_session__new(file, false, NULL);
      if (session == NULL) {
-        pr_err("Not enough memory for reading perf file header\n");
+        pr_err("Perf session creation failed.\n");
          return -1;
      }

tools/perf/util/data.c +1 -0

index 1fbcd8b..ff2ced7 100644
@@ -86,10 +86,16 @@ static int open_file_read(struct perf_data_file *file)
 
  static int open_file_write(struct perf_data_file *file)
  {
+    int fd;
      if (check_backup(file))
          return -1;

tools/perf/util/data.c static int open_file_read(struct perf_data_file *file) · line 101

Quoted 10 lines

tools/perf/util/data.c +6 -1

-    return open(file->path, O_CREAT|O_RDWR|O_TRUNC, S_IRUSR|S_IWUSR);
+    fd = open(file->path, O_CREAT|O_RDWR|O_TRUNC, S_IRUSR|S_IWUSR);
+
+    if (fd < 0)
+        pr_err("failed to open %s : %s\n", file->path, strerror(errno));
+
+    return fd;
  }
 
  static int open_file(struct perf_data_file *file)

--
To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html