Re: x86-64: Kernel with large page size

[Andi Kleen]

Subrahmanyam Ongole <songole@xxxxxxxxx> writes:

> When we run our application on AMD Opteron processors, we are seeing a
> large number of   L1_AND_L2_DTLB_MISSES. We used oprofile to measure
> these numbers.
>
> We wanted to try with a bigger page size and see if we could bring it
> down. TLB caches 4k page translations. I don't  know if larger page

You can use large pages in your application by mmaping
from a file in hugetlbfs and configuring large pages using sysctl.

> size would even help here.

It probably wouldn't because Opteron has much more 4K DTLB entries
than 2M DTLB entries. I have had people trying the opposite from
what you tried (using 4K pages for the kernel instead of 2MB),
but that also doesn't work right now.

-Andi

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