Re: Adding pool_cache_invalidate_local() to pool_cache(9) API

[Jason Thorpe <thorpej%shagadelic.org@localhost>]

On Oct 9, 2009, at 7:35 AM, Matt Thomas wrote:

> Do it lazily.  Set a flag in each per-cpu queue and next time an item that
> cpu accesses its per-cpu cache, it can see the cache is invalid and discard 
> it.
> This doesn't solve the window of that cpu already actively using the pool
> while the flag is set but it could that could solved by get testing the test 
> on
> exit, if set discarding the item, and retrying.
> 
> No reason for exposing the mechanics of how to do this to the users of the
> poll APIs.

It actually turned out to be very trivial to fix pool_cache_invalidate() to 
DTRT with per-CPU caches.  I'll provide a patch for Jean-Yves to try in the 
situation where he required pool_cache_invalidate_local().  While I was at it, 
I discovered that the two existing uses of pool_cache_invalidate() don't do 
proper synchronization wrt. the constructor.  I'll write up a patch for the 
alpha and x86 pmaps separately.

-- thorpej