+ linux-nvdimm
Original mail at
https://lkml.kernel.org/r/3f28adee-8214-fa8e-b368-eaf8b1934...@huawei.com
On Tue, Apr 13, 2021 at 02:25:58PM +0800, Kemeng Shi wrote:
> I'm using AEP with dax_kmem drvier, and AEP is export as a NUMA node in
What is AEP?
> my system. I will move cold pages from DRAM node to AEP node with
> move_pages system call. With old "rep movsq', it costs 2030ms to move
> 1 GB pages. With "movnti", it only cost about 890ms to move 1GB pages.
So there's __copy_user_nocache() which does NT stores.
> - ALTERNATIVE "jmp copy_page_regs", "", X86_FEATURE_REP_GOOD
> + ALTERNATIVE_2 "jmp copy_page_regs", "", X86_FEATURE_REP_GOOD, \
> + "jmp copy_page_nt", X86_FEATURE_XMM2
This makes every machine which has sse2 do NT stores now. Which means
*every* machine practically.
The folks on linux-nvdimm@ should be able to give you a better idea what
to do.
HTH.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
