Re: Mysterious memory corruption bug

[Bean]

On Wed, May 2, 2012 at 4:16 AM, Vladimir 'φ-coder/phcoder' Serbinenko
<address@hidden> wrote:
> On 01.05.2012 22:09, Bean wrote:
>> On Wed, May 2, 2012 at 4:06 AM, Vladimir 'φ-coder/phcoder' Serbinenko
>> <address@hidden> wrote:
>>> On 01.05.2012 22:02, Bean wrote:
>>>> Hi,
>>>>
>>>> Yeah, I have a patch that save the buffer for later use when there is
>>>> no data, it can solve the unnecessary alloc/free loop.
>>> No, what I mean: allocate a buffer once for every card and then do
>>> send/recv with only this buffer and copy to/from it when necessary. This
>>> way if the card DMAs the packet to the same buffer it won't corrupt
>>> anything.
>> Hi,
>>
>> It's not ok with fragmentation, since there could be multiple ethernet
>> packet for an ip packet, we need to store the buffer for assembling.
> We use the buffer I said only for actual calls. It's copied to
> newly-allocated packet as soon as the call returns.

Hi,

Yeah, after more thought, it's doable. We can use a ring buffer for
current active ip frames, and copy ethernet frame to it. This way we
can get rid of the rsm dynamic queue. It can also get rid of tons of
grub_netbuff_free scattered around in various layers.

-- 
Best wishes
Bean