kern/181632: 9.2-RC3 - on resume from suspend, disk operations are slower

[Mike Harding]

>Number:         181632
>Category:       kern
>Synopsis:       9.2-RC3 - on resume from suspend, disk operations are slower
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Aug 29 01:40:00 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator:     Mike Harding
>Release:        9.2-RC3
>Organization:
>Environment:
FreeBSD bsd.mvh 9.2-RC3 FreeBSD 9.2-RC3 #0 r254986: Wed Aug 28 09:05:42 PDT 2013     root at bsd.mvh:/usr/obj/usr/src/sys/GENERIC  amd64
>Description:
I've been using 'zzz' with a WOL for a while to keep my machine available, but not drawing a lot of power.  I recently installed 9.2-RC3.  It takes about 47 minutes to do a 'make -j9 buildworld buildkernel' on this machine, but if I do a suspend and resume, it takes much longer to do this same operation after the machine comes back up - for example, it took 1 hour 37 minutes to do the same buildkernel/buildworld after the resume from suspend.

It looks like the 'rm' operations are happening especially slowly - there is not much disk or CPU activity going on when I see 'rm' on the terminal, vs. before the 'zzz', when the disk and/or CPU seem pretty busy most of the time during the build.

I know that suspend/resume is a bit flaky, but it's been pretty reliable for me under 9.1.
>How-To-Repeat:
as root
cd /usr/src
rm -rf /usr/obj
time make -j9 buildworld buildkernel
zzz
(wake up the box)
(repeat the above)
>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: