On Mon, Aug 26, 2013 at 06:31:35PM +0530, Aneesh Kumar K.V wrote: > Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> writes: > > > On Thu, Aug 22, 2013 at 12:38:12PM +0530, Aneesh Kumar K.V wrote: > >> Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> writes: > >> > >> > Hello, Aneesh. > >> > > >> > First of all, thank you for review! > >> > > >> > On Wed, Aug 21, 2013 at 02:58:20PM +0530, Aneesh Kumar K.V wrote: > >> >> Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> writes: > >> >> > >> >> > If we alloc hugepage with avoid_reserve, we don't dequeue reserved one. > >> >> > So, we should check subpool counter when avoid_reserve. > >> >> > This patch implement it. > >> >> > >> >> Can you explain this better ? ie, if we don't have a reservation in the > >> >> area chg != 0. So why look at avoid_reserve. > >> > > >> > We don't consider avoid_reserve when chg != 0. > >> > Look at following code. > >> > > >> > + if (chg || avoid_reserve) > >> > + if (hugepage_subpool_get_pages(spool, 1)) > >> > > >> > It means that if chg != 0, we skip to check avoid_reserve. > >> > >> when whould be avoid_reserve == 1 and chg == 0 ? > > > > In this case, we should do hugepage_subpool_get_pages(), since we don't > > get a reserved page due to avoid_reserve. > > As per off-list discussion we had around this, please add additional > information in commit message explaining when we have > avoid_reserve == 1 and chg == 0 Okay! > > Something like the below copied from call site. > > /* If the process that created a MAP_PRIVATE mapping is about to > * perform a COW due to a shared page count, attempt to satisfy > * the allocation without using the existing reserves > */ > > Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> Thanks. -- 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>