On Wed, May 07, 2008 at 08:10:33PM -0700, Christoph Lameter wrote:When it looked like we could use vm_flags to remove sort, that looked an ok optimization, no problem with optimizations, I'm all for optimizations if they cost nothing to the VM fast paths and VM footprint. But removing sort isn't worth it if it takes away ram from the VM even when global_mm_lock will never be called. sort is like /dev/urandom so after sort is fixed to handle signals (and I expect Matt will help with this) we'll remove the 512 vmas cap. In the meantime we can live with the 512 vmas cap that guarantees sort won't take more than a few dozen usec. Removing sort() is the only thing that the anon vma bitflag can achieve and it's clearly not worth it and it would go in the wrong direction (fixing sort to handle signals is clearly the right direction, if sort is a concern at all). Adding the global lock around global_mm_lock to avoid one global_mm_lock to collide against another global_mm_lock is sure ok with me, if that's still wanted now that it's clear removing sort isn't worth it, I'm neutral on this. Christoph please go ahead and add the bitflag to anon-vma yourself if you want. If something isn't technically right I don't do it no matter who asks it. --
| H. Peter Anvin | Re: [RFC 00/15] x86_64: Optimize percpu accesses |
| Tarkan Erimer | Re: Dual-Licensing Linux Kernel with GPL V2 and GPL V3 |
| Eric W. Biederman | Remaining straight forward kthread API conversions... |
| Greg Kroah-Hartman | [PATCH 001/196] Chinese: Add the known_regression URI to the HOWTO |
| David Miller | [GIT]: Networking |
| Gerrit Renker | [PATCH 27/37] dccp: Integration of dynamic feature activation - part 2 (server side) |
| David Miller | Re: [PATCH] pkt_sched: Destroy gen estimators under rtnl_lock(). |
| Frans Pop | svc: failed to register lockdv1 RPC service (errno 97). |
git: | |
