Hi Michal, On Thu, Sep 06, 2012 at 02:59:53PM +0200, Michal Nazarewicz wrote: > > On Wed, Sep 05, 2012 at 07:28:23PM +0200, Michal Nazarewicz wrote: > >> If you ask me, I'm not convinced that this improves anything. > > On Thu, Sep 06 2012, Minchan Kim wrote: > > At least, it removes MIGRATE_ISOLATE type in free_area->free_list > > which is very irony type as I mentioned. I really don't like such > > type in free_area. What's the benefit if we remain code as it is? > > It could make more problem in future. > > I don't really see current situation as making more problems in the > future compared to this code. > > You are introducing a new state for a page (ie. it's not in buddy, but > in some new limbo state) and add a bunch of new code and thus bunch of > new bugs. I don't see how this improves things over having generic > code that handles moving pages between free lists. > > PS. free_list does exactly what it says on the tin -> the pages are > free, ie. unallocated. It does not say that they can be allocated. ;) I saw two bug report about MIGRATE_ISOALTE type and NR_FREE_PAGES accounting mistmatch problem until now and I think we can meet more problems in the near future without solving it. Maybe, [1] would be a solution but I really don't like to add new branch in hotpath, even MIGRATE_ISOLATE used very rarely. so, my patch is inpired. If there is another good idea that avoid new branch in hotpath and solve the fundamental problem, I will drop this patch. Thanks. [1] http://permalink.gmane.org/gmane.linux.kernel.mm/85199. -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>