Re: USB: hub: Delete an error message for a failed memory allocation in usb_hub_clear_tt_buffer()

Alan Stern
2017-12-06T22:02:42Z

On Wed, 6 Dec 2017, SF Markus Elfring wrote:

> >>> Does the existing memory allocation error message include the
> >>> &udev->dev device name and driver name? If it doesn't, there will be
> >>> no way for the user to tell that the error message is related to the
> >>> device failure.
> >>
> >> No, but the effect is similar.
> >>
> >> OOM does a dump_stack() so this function's call tree is shown.
> >
> > A call stack doesn't tell you which device was being handled.
>
> Do you find a default Linux allocation failure report insufficient then?
>
> Would you like to to achieve that the requested information can be determined
> from a backtrace?

It is not practical to do this. The memory allocation routines do not
for what purpose the memory is being allocated; hence when a failure
occurs they cannot tell what device (or other part of the system) will
be affected.

That's why we have a secondary error message.

Alan Stern