[lkml]   [2018]   [May]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH -mm] mm, huge page: Copy to access sub-page last when copy huge page
On 05/17/2018 11:24 PM, Michal Hocko wrote:
> On Fri 18-05-18 11:03:16, Huang, Ying wrote:
> [...]
>> The patch is a generic optimization which should benefit quite some
>> workloads, not for a specific use case. To demonstrate the performance
>> benefit of the patch, we tested it with vm-scalability run on
>> transparent huge page.
> It is also adds quite some non-intuitive code. So is this worth? Does
> any _real_ workload benefits from the change?

One way to 'add less code' would be to create a helper routine that
indicates the order in which sub-pages are to be copied. IIUC, you
added the same algorithm for sub-page ordering to copy_huge_page()
that was previously added to clear_huge_page(). Correct? If so,
then perhaps a common helper could be used by both the clear and copy
huge page routines. It would also make maintenance easier.

Mike Kravetz

 \ /
  Last update: 2018-05-18 18:42    [W:0.078 / U:2.372 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site