Re: [PATCH] ethernet: mlx4: Delete an error message for a failed memory allocation in five functions

Jason Gunthorpe
2018-01-03T16:03:16Z

On Wed, Jan 03, 2018 at 01:24:59PM +0200, Tariq Toukan wrote:

> >Strings take up space. Since there is a backtrace on an out of memory
> >problem, if the string does not provide any more information than the
> >position of the call, then there is not much added value. I don't know
> >what was the string in this case. If it provides some additional
> >information, then it would be reasonable to keep it.
>
> I don't really accept this claim...

The standard we are moving to is to rely on the backtrace print for
debugging. It is so huge it is unlikely a single print from the driver
will make much difference to the user's view.

Most users think backtrace = oops = bug report.

> In addition, some out-of-memory errors are recoverable, even though their
> backtrace is also printed. For example, in function mlx4_en_create_cq
> (appears in patch) we have a first allocation attempt (kzalloc_node) and a
> fallback (kzalloc).

Please send a patch fixing this as other have suggested, it is clearly
a bug.

Jason