On Wed, Sep 05, 2012 at 05:11:13PM +0900, Minchan Kim wrote: > This patch introudes MIGRATE_DISCARD mode in migration. > It drops *clean cache pages* instead of migration so that > migration latency could be reduced by avoiding (memcpy + page remapping). > It's useful for CMA because latency of migration is very important rather > than eviction of background processes's workingset. In addition, it needs > less free pages for migration targets so it could avoid memory reclaiming > to get free pages, which is another factor increase latency. >
Bah, this was released while I was reviewing the older version. I did not read this one as closely but I see the enum problems have gone away at least. I'd still prefer if CMA had an additional helper to discard some pages with shrink_page_list() and migrate the remaining pages with migrate_pages(). That would remove the need to add a MIGRATE_DISCARD migrate mode at all. -- Mel Gorman SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
