Re: [PATCH] __free_pages_ok oops

[Benjamin LaHaise <bcrl@redhat.com>]

On Wed, Feb 06, 2002 at 10:19:32PM -0800, Andrew Morton wrote:
> It's only a problem if this is the final put_page().  In the
> case of sendfile(), process-context code can be taught to take
> a temporary reference on the page, and only release it after the network
> stack is known to have finished with the page. sendfile is synchronous, yes?
> 
> And in the case of all other skb frees, the underlying page
> won't be on the LRU.  I hope.

sendfile isn't synchronous, nor is aio, which also relies on freeing pages 
acquired from user mappings in irq/bh/whatever context.  Restricting where 
pages may be freed really ties our hands on what is possible for zero copy 
io. (ie O_DIRECT, aio, sendfile, TUX all get hosed by this).

		-ben (who is really on vacation)
-- 
begin 644 fish.com
866]U(&AA=F4@=&]O(&UU8V@@=&EM92X*
`
end