Bug 127451

Summary:	[scheduler] incorrect load on quad core
Product:	Base System	Reporter:	Miks <miks>
Component:	amd64	Assignee:	freebsd-amd64 (Nobody) <amd64>
Status:	Closed FIXED
Severity:	Affects Only Me
Priority:	Normal
Version:	Unspecified
Hardware:	Any
OS:	Any

Description Miks 2008-09-17 22:50:01 UTC

I got load average around 0.5, and top show something like this
"1021 processes: 1 running, 1020 sleeping
CPU states:  4.9% user,  0.0% nice,  3.6% system,  0.9% interrupt,
90.6% idle" - this all is ok.

then once in 2-5 minutes, there for 2-3 seconds are:
"1020 processes:67 running, 912 sleeping, 1 zombie, 40 lock
CPU states:  3.0% user,  0.0% nice, 96.7% system,  0.3% interrupt,
0.0% idle" - this is the problem.

after this load average is 20-30 and dropping in 2-3min to 0.5. during
this time system is very slow. even ssh session is freezing.
most of processes are fastcgi/php, so there is not one big resource
hungry process.

found similar problem here: http://unix.derkeiler.com/Mailing-Lists/FreeBSD/stable/2007-11/msg00551.html

Comment 1 Miks 2008-09-18 19:50:06 UTC

problem name is not correct - "top(1): incorrect load shown on quad core"
I believe with top command there everything is ok.
Problem is that after 2 or 3 minutes system suddenly got ~60 running  
proceses, ~40 locks and cpu is ~90% busy system, not user. system is  
unusable. old dual core system was faster and more stable than brand  
new dual quad-core cpu with 16gb ram.
So problem by the fact is totally different, and I can't figure where  
and what is responsible for new, powerful server acting as low-budget  
desktop computer.

Comment 2 Miks 2008-09-18 20:22:56 UTC

to understand better, this happen once in 2-3 minutes:
"
last pid: 98618;  load averages: 29.81, 17.28, 15.03    up 6+23:13:22   
22:15:50
1234 processes:159 running, 986 sleeping, 64 zombie, 25 lock
CPU states:  1.1% user,  0.0% nice, 98.8% system,  0.0% interrupt,  0.0% idle
"
before 3 sec in this situation there was only 1 process running and  
load average was around 1.

is it somehow related with lockmgr?

Comment 3 Andriy Gapon freebsd_committer

2010-12-05 11:15:51 UTC

Is this still reproducible?
What kind of processes are running when that happens?
top -SPH output may be of help.

-- 
Andriy Gapon

Comment 4 Miks 2010-12-06 20:20:11 UTC

 No,  it's not happening anymore.

On 2010.12.05, at 13:15, Andriy Gapon wrote:

>=20
> Is this still reproducible?
> What kind of processes are running when that happens?
> top -SPH output may be of help.
>=20
> --=20
> Andriy Gapon

--=20
Miks Mi=F3elsons

SKYNET
web:   =20
http://www.skynet.lv

email: =20
miks@skynet.lv

GSM: +371 2 86 48 669

Comment 5 Andriy Gapon freebsd_committer

2010-12-06 21:43:31 UTC

State Changed
From-To: open->closed

iClosing per submitter's feedback, the issue seems to be resolved.