Re: [RFC 0/3] ARM: copy_{from,to}_user() for vmsplit 4g/4g

afzal mohammed
2020-06-12T16:02:23Z

Hi,

On Fri, Jun 12, 2020 at 11:19:23AM -0400, Nicolas Pitre wrote:
> On Fri, 12 Jun 2020, afzal mohammed wrote:

> > Performance wise, results are not encouraging, 'dd' on tmpfs results,

> Could you compare with CONFIG_UACCESS_WITH_MEMCPY as well?

512 1K 4K 16K 32K 64K 1M

normal 30 46 89 95 90 85 65

uaccess_w_memcpy 28.5 45 85 92 91 85 65

w/ series 22 36 72 79 78 75 61

There are variations in the range +/-2 in some readings when repeated,
not put above, to keep comparison simple.

Regards
afzal