Re: [PATCH v2 0/3] x86/fred: enable FRED by default

[H. Peter Anvin]

On 2026-03-26 15:11, Andy Lutomirski wrote:
> 
> Those performance increases while with fio / io_uring are ridiculous.  I wonder whether anyone can looked at /proc/interrupts to try to figure out what's going on.  I imagine we're bottlenecking on IO interrupts or something and FRED speeds that up by a factor of several, but this makes me wonder whether there's some tuning that should be done.
> 
> Jens, for background, FRED ought to speed up page faults and interrupts (both IPI and device) by a considerable amount -- maybe a reduction of 20k or more cycles per interrupt.  But Phoronix is showing up to a factor of 2 (!) actual performance increase using io_uring with a job count of 8.  Now maybe 8 is too small, but I'm wondering whether the io_uring or IO part is missing some optimization that it ought to have.
> 

Hi Andy! Long time no C!

Either way, I presume neither of you have any problems with the patchset itself?

	-hpa