Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting

Alexander Shishkin
2015-09-11T16:12:09Z

Arnaldo Carvalho de Melo <acme@kernel.org> writes:

> Em Wed, Aug 26, 2015 at 07:56:47PM +0300, Alexander Shishkin escreveu:
>> So I hacked stuff a bit [1] to accomodate some of the above
>> ideas. The below diff shows how these ideas integrate with perf. The
>> rest is in my github tree.
>>
>> - this exterr implementation allows its users to add arbitrary
>> information to the call site structures and also pretty print them on
>> the way out; in the example, perf stores perf_event_attr field name
>> that is the source of trouble; it's a string rather than offsetof(),
>> because half of our event attribute is a bit field;
>> - the "way out" doesn't have to be syscall return path (although in the
>> example it is);
>> - userspace can fetch the extended error reports via prctl() like you
>> suggested above;
>> - error codes are still passed around in the [-EXT_ERRNO..-MAX_ERRNO]
>> range until they are passed to userspace (which is where ext_err_code()
>> converts them back to traditional errno.h values).
>
> Hey, can we see the builtin-record.c patch please?

Should be on the way to your inbox.

Cheers,
--
Alex