[openib-general] Re: [PATCH] sdp: replace mlock with get_user_pages

[Libor Michalek]

On Thu, Jul 21, 2005 at 10:51:54AM +0300, Michael S. Tsirkin wrote:
> Hello, Libor!
> Here's a patch updated against the latest bits.
> I'd like it to get merged, if possible.
> 
> The existing code play with VMA's is the #1 source of sdp problems for me.
> The patch below works with no problems for me, so far.
> 
> Please comment.

Michael,

  Looking at sdp_iocb_unlock() I see that you attempt to perform the
get_user_pages() for the full buffer before checking to see if the
pages need copying, but if that fails you perform it a page at a time
iterating through the list. Are you seeing this on a regular basis,
that the full get fails, but then the iteration over the list works?
Do you know what's causing this to happen, and whay the second iteration
fixes it?

Thanks.

-Libor