9.2-RC3 - suspend/resume causes slow system performance

[Andriy Gapon]

on 02/09/2013 00:58 Adrian Chadd said the following:
> On 1 September 2013 14:35, Andriy Gapon <avg at freebsd.org
> <mailto:avg at freebsd.org>> wrote:
>  
> 
>     Do you have any evidence that there is anybody else besides Mike who has this
>     problem?
> 
> 
> 
> Nope! but we can't assume that users are reporting all the system slowdowns.

Why?

> And honestly, I've heard enough strange stories on mailing lists and IRC of
> things like "during disk IO, blah would be really slow, when I change
> timekeeping or halt from ACPI to something else, things get better." So I can't
> discount that this is affecting people and they either don't know, or just chalk
> it up as "shitty hardware."

Strange stories are just that.

>     Also, I usually try to "sort out" things after there is a clear understanding of
>     what the problem is and how it should be fixed.
> 
> 
> Well, the big change is that it's now going into a sleep state on a HT core, right?
> 
> Are you able to go into an ACPI sleep state on a HT logical CPU, rather than the
> physical core? Or am I mis-understanding what's going on?

Most likely.  I do not see how the change is HT-specific or HT-related at all.

> 
>     > Reverting and fixing it later seems like the safest option to me. Is there a
>     > bigger problem that you tried to fix in that patch that wasn't as obvious?
> 
>     I do not see any problem with the code*.*  I do not see any explanation of the
>     root cause of the problem that Mike has.  I do not see why anything has to be
>     reverted.  Especially because "since we're so close to 9.2-REL".
>     Just in case, I'll remind that the commit in question is in stable/9 since Dec
>     23 2012.
> 
> 
> Right, but I also know a lot of people who just have stayed with 8.x or
> 9.0-RELEASE and haven't bothered upgrading. Again, I can't assume that everyone
> has been keeping up to date with stable/9 and providing feedback.

I am positive that it's not everyone who uses (up-to-date) stable/9.  Still, I
believe that a user-base of stable/9 is >> 1.

-- 
Andriy Gapon