On 21.07.2017 16:47, Theodore Ts'o wrote:
On Fri, Jul 21, 2017 at 01:39:13PM +0200, Oliver Mangold wrote:
Better, but obviously there is still much room for improvement by reducing
the number of calls to RDRAND.
Hmm, is there some way we can easily tell we are running on Ryzen? Or
On 21.07.2017 11:26, Jan Glauber wrote:
Nice catch. How much does the performance improve on Ryzen when you
use arch_get_random_int()?
Okay, now I have some results for you:
On Ryzen 1800X (using arch_get_random_int()):
---
# dd if=/dev/urandom of=/dev/null bs=1M status=progress
8751415296 b
Hi,
I was wondering why reading from /dev/urandom is much slower on Ryzen
than on Intel, and did some analysis. It turns out that the RDRAND
instruction is at fault, which takes much longer on AMD.
if I read this correctly:
--- drivers/char/random.c ---
862 spin_lock_irqsave(&crn
