On Wed, 2005-12-14 at 10:22 +0100, Andi Kleen wrote: > > I would appreciate any feedback or comments on this approach. > > Maybe I'm missing something but wouldn't you need an own critical > pool (or at least reservation) for each socket to be safe against deadlocks? > > Otherwise if a critical sockets needs e.g. 2 pages to finish something > and 2 critical sockets are active they can each steal the last pages > from each other and deadlock.
Here we are assuming that the pre-allocated critical page pool is big enough to satisfy the requirements of all the critical sockets. In the current critical page pool implementation, there is also a limitation that only order-0 allocations(single page) are supported. I think in the networking send/receive patch, the only place where multi-page allocs are requested is in the drivers if the MTU > PAGESIZE. But i guess the drivers are getting updated to avoid > order-0 allocations. Also during the emergency, we free the memory allocated for non-critical packets as quickly as possible so that it can be re-used for critical allocations. Thanks Sridhar - 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
