On 06/09/2016 08:04 PM, Mel Gorman wrote:
The vmstat allocstall was fairly useful in the general sense but node-based LRUs change that. It's important to know if a stall was for an address-limited allocation request as this will require skipping pages from other zones. This patch adds pgstall_* counters to replace allocstall. The sum of the counters will equal the old allocstall so it can be trivially recalculated. A high number of address-limited allocation requests may result in a lot of useless LRU scanning for suitable pages. As address-limited allocations require pages to be skipped, it's important to know how much useless LRU scanning took place so this patch adds pgskip* counters. This yields the following model 1. The number of address-space limited stalls can be accounted for (pgstall) 2. The amount of useless work required to reclaim the data is accounted (pgskip) 3. The total number of scans is available from pgscan_kswapd and pgscan_direct so from that the ratio of useful to useless scans can be calculated. Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Nice work! -- 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>