On Wed, Feb 03, 2016 at 02:43:16PM -0800, Andrew Morton wrote: > On Wed, 3 Feb 2016 07:42:01 -0800 Dave Hansen <dave.hansen@xxxxxxxxx> wrote: > > > On 02/03/2016 07:14 AM, Kirill A. Shutemov wrote: > > > But the new variant is somewhat slower. Current helpers iterates over > > > VMAs the compound page is mapped to, and then over ptes within this VMA. > > > New helpers iterates over small page, then over VMA the small page > > > mapped to, and only then find relevant pte. > > > > The code simplification here is really attractive. Can you quantify > > what the slowdown is? Is it noticeable, or would it be in the noise > > during all the other stuff that happens under memory pressure? > > yup. It is not really clear, how to quantify this properly. Let me think more about it. > And the "more testing is required" is a bit worrisome. Is this > code really ready for getting pounded upon in -next? By now it survived 5+ hours of fuzzing in 16 VM in parallel. I'll continue with other tests tomorrow. -- Kirill A. Shutemov -- 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>