On Thu, Jul 07, 2016 at 02:51:21PM +0900, Minchan Kim wrote: > > It becomes difficult to tell the difference between "no wakeup and init to > > zone 0" and "wakeup and reclaim for zone 0". At least that's the problem > > I ran into when I tried before settling on -1. > > Sorry for bothering you several times. I cannot parse what you mean. > I didn't mean -1 is problem here but why do we need below two lines > I removed? > What you have should be fine. The hazard initially was that both classzone_idx and kswapd_classzone_idx are enum and the signedness of enum is implementation-dependent. Using max_t avoids that but it's a subtle. I prefer the obvious check of kswapd_classzone_idx == 1 because it is clearer that we're checking for an initialised value instead of depending on a side-effect of the casting in max_t to do the right thing. I can apply it if you wish, I just don't think it helps. -- Mel Gorman SUSE Labs -- 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>