On 04/16/2015 06:22 AM, Mel Gorman wrote: > Page reclaim batches multiple TLB flushes into one IPI and this patch teaches > page migration to also batch any necessary flushes. MMtests has a THP scale > microbenchmark that deliberately fragments memory and then allocates THPs > to stress compaction. It's not a page reclaim benchmark and recent kernels > avoid excessive compaction but this patch reduced system CPU usage > > 4.0.0 4.0.0 > baseline batchmigrate-v1 > User 970.70 1012.24 > System 2067.48 1840.00 > Elapsed 1520.63 1529.66 > > Note that this particular workload was not TLB flush intensive with peaks > in interrupts during the compaction phase. The 4.0 kernel peaked at 345K > interrupts/second, the kernel that batches reclaim TLB entries peaked at > 13K interrupts/second and this patch peaked at 10K interrupts/second. > > Signed-off-by: Mel Gorman <mgorman@xxxxxxx> Reviewed-by: Rik van Riel <riel@xxxxxxxxxx> -- 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>