Messages in this thread | | | From | "Jason A. Donenfeld" <> | Date | Sun, 13 Feb 2022 22:04:17 +0100 | Subject | Re: [PATCH v6] random: defer fast pool mixing to worker |
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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
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