On Wed, 23 Jan 2013 18:44:52 +0800 Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxxxxxx> wrote: > On 01/23/2013 06:12 PM, Takuya Yoshikawa wrote: > > This patch set mitigates another mmu_lock hold time issue. Although > > this is not enough and I'm thinking of additional work already, this > > alone can reduce the lock hold time to some extent. > > > > It is not worth doing this kind of complex thing, usually, only a few pages on > the invalid list. The *really* heavily case is kvm_mmu_zap_all() which can be speeded > up by using generation number, this is a todo work in kvm wiki: I don't think this is so complex. This is a basic programming technique using linked lists. The current code which deletes the two link nodes in different functions looks unnatural to me: traversing the sp->link nodes forces us to break the loop and sp->hash_link nodes alone is allowed to continue ... Making each function semantically clear should be more important than other things. But maybe a matter of taste, so I'll wait for the maintainers' comments. > http://www.linux-kvm.org/page/TODO: O(1) mmu invalidation using a generation number > > I am doing this work for some weeks and will post the patch out during these days. I remember that Avi originally wrote the idea of introducing the generation of mmu pages in his other work. Thanks, Takuya -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
