<html> <head> <meta content="text/html; charset=utf-8" http-equiv="Content-Type"> </head> <body text="#000000" bgcolor="#FFFFFF"> <div class="moz-cite-prefix">On 2017年05月10日 05:47, Kasiviswanathan, Harish wrote: </div> <blockquote cite="mid:DM3PR1201MB10382F282D646D630708246D8CEF0@DM3PR1201MB1038.namprd12.prod.outlook.com" type="cite"> <pre wrap="">Hi, Please review the patch set that supports amdgpu VM update via CPU. This feature provides improved performance for compute (HSA) where mapping / unmapping is carried out (by Kernel) independent of command submissions (done directly by user space). This version doesn't support shadow copy of VM page tables for CPU based update.</pre> </blockquote> I think your improved performance is from less waiting for cs, generally, SDMA engine updating page table is faster than CPU, otherwise we don't need sdma for updating PT. So whether your this improvement proves we have some redundant sync when mapping / unmapping, if yes, we should fix that, then not sure if CPU method is need or not. Regards, David Zhou <blockquote cite="mid:DM3PR1201MB10382F282D646D630708246D8CEF0@DM3PR1201MB1038.namprd12.prod.outlook.com" type="cite"> <pre wrap=""> Best Regards, Harish </pre> <fieldset class="mimeAttachmentHeader"></fieldset> <pre wrap="">_______________________________________________ amd-gfx mailing list <a class="moz-txt-link-abbreviated" href="mailto:amd-gfx@lists.freedesktop.org">amd-gfx@lists.freedesktop.org</a> <a class="moz-txt-link-freetext" href="https://lists.freedesktop.org/mailman/listinfo/amd-gfx">https://lists.freedesktop.org/mailman/listinfo/amd-gfx</a> </pre> </blockquote> </body> </html>