Re: Memory coherency issue with IO thread offloading?

On 3/24/23 6:15 PM, Michael Ellerman wrote:

Jens Axboe [off-list ref] writes:

quoted

On 3/24/23 1:27?AM, Christophe Leroy wrote:

quoted

Le 23/03/2023 ? 19:54, Jens Axboe a ?crit :

quoted

I got a report sent to me from mariadb, in where 5.10.158 works fine and
5.10.162 is broken. And in fact, current 6.3-rc also fails the test
case. Beware that this email is long, as I'm trying to include
everything that may be relevant...

Which variant of powerpc ? 32 or 64 bits ? Book3S or BookE ?

I knew I'd forget something important... It's power9:

processor	: 0
cpu		: POWER9 (architected), altivec supported
clock		: 2200.000000MHz
revision	: 2.2 (pvr 004e 1202)

Believe it or not there's still more variables in play, Power9 has two
different MMUs, and Linux can run on two different hypervisors as well
as on bare metal P9 :)

Just my luck :-)

Can you paste the last ~10 lines of /proc/cpuinfo, with the "machine",
"firmware" and "MMU" lines, that should tell us everything we need to
know.

timebase	: 512000000
platform	: pSeries
model		: IBM pSeries (emulated by qemu)
machine		: CHRP IBM pSeries (emulated by qemu)
MMU		: Radix

I know it reproduces bare metal as well, but no details on what
that box is. I just know I was able to reproduce it in this vm that
I was able to get my hands on.

-- 
Jens Axboe