From: Nick Piggin <[EMAIL PROTECTED]> Date: Fri, 4 Jan 2008 12:33:52 +0100
> Just for interest, the lockless pagecache actually makes > page->_count unstable for all pages that _have ever_ been pagecache > pages (since the last quiescent rcu state, anyway). Basically, it > looks up and takes a ref on the struct page without ever having a > prior pin or reference on that page. It can do this because it knows > the struct page won't actually get freed. After taking the ref, it > rechecks that it has got the right page... Ok, I understand the needs now. I think the way the drivers/net/niu.c driver handles things would work better. It only performs get_page(), atomic increments on compound_head(page)->_count, and __free_page(). Is that all legal with the lockless pagecache? If so I can likely rework the Cassini page management to behave similarly. > Acked-by: Nick Piggin <[EMAIL PROTECTED]> Thanks for reviewing. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
