Thanks for all the feedback from everyone. I am going to try to fix this up, and do some more robust benchmarking, including the 2MB case, and try to have an updated/non-RFC patch(es) in a few days. Thanks! Cannon On Mon, Jul 30, 2018 at 9:29 AM Borislav Petkov <bp@xxxxxxxxx> wrote: > > On Tue, Jul 24, 2018 at 07:37:28PM -0700, Cannon Matthews wrote: > > diff --git a/arch/x86/lib/clear_page_64.S b/arch/x86/lib/clear_page_64.S > > index 88acd349911b..81a39804ac72 100644 > > --- a/arch/x86/lib/clear_page_64.S > > +++ b/arch/x86/lib/clear_page_64.S > > @@ -49,3 +49,23 @@ ENTRY(clear_page_erms) > > ret > > ENDPROC(clear_page_erms) > > EXPORT_SYMBOL_GPL(clear_page_erms) > > + > > +/* > > + * Zero memory using non temporal stores, bypassing the cache. > > + * Requires an `sfence` (wmb()) afterwards. > > + * %rdi - destination. > > + * %rsi - page size. Must be 64 bit aligned. > > +*/ > > +ENTRY(__clear_page_nt) > > + leaq (%rdi,%rsi), %rdx > > + xorl %eax, %eax > > + .p2align 4,,10 > > + .p2align 3 > > +.L2: > > + movnti %rax, (%rdi) > > + addq $8, %rdi > > + cmpq %rdx, %rdi > > + jne .L2 > > + ret > > +ENDPROC(__clear_page_nt) > > +EXPORT_SYMBOL(__clear_page_nt) > > EXPORT_SYMBOL_GPL like the other functions in that file. > > -- > Regards/Gruss, > Boris. > > ECO tip #101: Trim your mails when you reply. > --
