On 23/11/16 03:25, Zi Yan wrote: > From: Zi Yan <zi.yan@xxxxxxxxxxxxxx> > > Hi all, > > This patchset boosts the hugepage migration throughput and helps THP migration > which is added by Naoya's patches: https://lwn.net/Articles/705879/. > > Motivation > =============================== > > In x86, 4KB page migrations are underutilizing the memory bandwidth compared > to 2MB THP migrations. I did some page migration benchmarking on a two-socket > Intel Xeon E5-2640v3 box, which has 23.4GB/s bandwidth, and discover > there are big throughput gap, ~3x, between 4KB and 2MB page migrations. > > Here are the throughput numbers for different page sizes and page numbers: > | 512 4KB pages | 1 2MB THP | 1 4KB page > x86_64 | 0.98GB/s | 2.97GB/s | 0.06GB/s > > As Linux currently use single-threaded page migration, the throughput is still > much lower than the hardware bandwidth, 2.97GB/s vs 23.4GB/s. So I parallelize > the copy_page() part of THP migration with workqueue and achieve 2.8x throughput. > > Here are the throughput numbers of 2MB page migration: > | single-threaded | 8-thread > x86_64 2MB | 2.97GB/s | 8.58GB/s > Whats the impact on CPU utilization? Is there a huge impact? Balbir Singh. -- 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>