On Mon, Jan 20, 2014 at 03:17:43PM +0000, Gordan Bobic wrote:
On 2014-01-20 14:51, Richard W.M. Jones wrote:
I never said that fixups were free, obviously going in and out of the kernel to emulate an instruction is going to take some time.
You seemed to imply it above by saying that penalty on recent x86 is non-existant on Sandy Bridge and insignificant on slightly less recent x86 CPUs.
I failing to see what Intel Sandybridge has to do with the ARM Cortex-A15 chips in Chromebooks, but anyway ...
The question is whether it noticably affects any code.
It certainly seems to affect the nss build process quite badly, specifically the test stage (which actually fails some tests on ARM, concerningly). Whether it affects the runtime I don't know, I don't think I use it - the only crypto related packages I use are OpenSSH and mod_ssl, both of which, AFAIK, link against OpenSSL rather than nss.
OK, sounds like nss needs to be fixed.
Rich.