lkml.org 
[lkml]   [2022]   [Feb]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v6] random: defer fast pool mixing to worker
Hey Sebastian,

On Fri, Feb 11, 2022 at 6:26 PM Sebastian Andrzej Siewior
<bigeasy@linutronix.de> wrote:
> Sure. I can do the CPU-HP notifier later one once we are done with
> everything. I acked the v7, don't see a road block.

I've been running this over the weekend and performance is generally okay.

# perf top --symbols $(objdump -t
/usr/src/linux/drivers/char/random.o|fgrep 'F .text'|awk '{print
$6}'|tr '\n' ,) -F max -g

One thing I noticed though was that add_interrupt_randomness spends
most of its time on:

lock xadd %eax,0x38(%rbp)

So, as expected, those atomics really need to go. Indeed we might be
best off with the CPU hotplug notifier for setting the count back to
zero.

Do you want to prepare a patch for this? Or should I take a stab at it?

Jason

\
 
 \ /
  Last update: 2022-02-13 22:05    [W:0.057 / U:0.156 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site