On Tue, 15 May 2018, Huang, Ying wrote: > From: Huang Ying <[email protected]> > > This is to take better advantage of huge page clearing > optimization (c79b57e462b5d, "mm: hugetlb: clear target sub-page last > when clearing huge page"). Which will clear to access sub-page last > to avoid the cache lines of to access sub-page to be evicted when > clearing other sub-pages. This needs to get the address of the > sub-page to access, that is, the fault address inside of the huge > page. So the hugetlb no page fault handler is changed to pass that > information. This will benefit workloads which don't access the begin > of the huge page after page fault. > > With this patch, the throughput increases ~28.1% in vm-scalability > anon-w-seq test case with 88 processes on a 2 socket Xeon E5 2699 v4 > system (44 cores, 88 threads). The test case creates 88 processes, > each process mmap a big anonymous memory area and writes to it from > the end to the begin. For each process, other processes could be seen > as other workload which generates heavy cache pressure. At the same > time, the cache miss rate reduced from ~36.3% to ~25.6%, the > IPC (instruction per cycle) increased from 0.3 to 0.37, and the time > spent in user space is reduced ~19.3% > > Signed-off-by: "Huang, Ying" <[email protected]> > Cc: Andrea Arcangeli <[email protected]> > Cc: "Kirill A. Shutemov" <[email protected]> > Cc: Andi Kleen <[email protected]> > Cc: Jan Kara <[email protected]> > Cc: Michal Hocko <[email protected]> > Cc: Matthew Wilcox <[email protected]> > Cc: Hugh Dickins <[email protected]> > Cc: Minchan Kim <[email protected]> > Cc: Shaohua Li <[email protected]> > Cc: Christopher Lameter <[email protected]> > Cc: "Aneesh Kumar K.V" <[email protected]> > Cc: Punit Agrawal <[email protected]> > Cc: Anshuman Khandual <[email protected]>
Acked-by: David Rientjes <[email protected]>
