Messages in this thread | | | Date | Tue, 30 Jul 2013 11:49:00 -0700 (PDT) | Subject | Re: [PATCH v3 1/3] net/usb/r815x: replace USB buffer from stack to DMA-able | From | David Miller <> |
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From: Joe Perches <joe@perches.com> Date: Tue, 30 Jul 2013 11:41:17 -0700
> On Tue, 2013-07-30 at 11:33 -0700, David Miller wrote: >> From: Greg KH <gregkh@linuxfoundation.org> >> Date: Tue, 30 Jul 2013 07:00:59 -0700 >> >> > This call is so slow, you can afford to make a call to kmalloc for the >> > data, as it sure just did for other structures it needed :) >> >> I told him to implement things this way, to avoid calling kmalloc every >> single register access. >> >> Using kmalloc all the time makes the access fragile, since a badly timed >> call during high memory pressure can fail. >> >> I'd rather the potential failure happen at one time, probe time. >> >> In any event, Ming Lei has suggested using usbnet_{read,write}_cmd() >> instead, which sounds like a good solution to this problem. > > Those do per-call allocs too.
Sigh... Ok I won't fight this any longer then :-)
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