Date: Thu, 14 Sep 2006 00:48:49 -0400 From: "Tamouh H." <hakmi@rogers.com> To: "'Giorgos Keramidas'" <keramida@ceid.upatras.gr> Cc: questions@freebsd.org, 'Ian Smith' <smithi@nimnet.asn.au> Subject: RE: Top not showing cpu usage even remotely accurately Message-ID: <20060914044821.1039743D45@mx1.FreeBSD.org> In-Reply-To: <20060810055227.GA7051@gothmog.pc>
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>=20
> In recent 6.X versions, you can use 'S' to show system threads too.
> For an even more fine-grained view, you can use 'H' to show=20
> each thread separately.
>=20
> Then there is also the 'CPU' mode (as opposed to the default 'WCPU'
> mode of top).
>=20
> > I've the same issue with FBSD 5.4 and TOP. In fact, the=20
> load averages=20
> > are so irrelevant now that I barely pay attention to them.=20
> The server=20
> > goes to 4 or 6 load averages without slowing down, and=20
> other times the=20
> > load average would be 0.8 and the server is running slow.
>=20
> Probably because the work it does at the moment is not CPU-bounded?
>=20
> > An example of unmatching TOP:
> >=20
> > last pid: 17889; load averages: 0.60, 0.52, 0.50 =20
> up 3+17:22:33 00:41:45
> > 186 processes: 2 running, 183 sleeping, 1 lock CPU states:=20
> 30.0% user, =20
> > 0.0% nice, 1.7% system, 0.1% interrupt, 68.3% idle
> > Mem: 1678M Active, 1110M Inact, 287M Wired, 87M Cache, 112M=20
> Buf, 103M=20
> > Free
> > Swap: 8762M Total, 1584K Used, 8760M Free
> >=20
> > PID USERNAME PRI NICE SIZE RES STATE C TIME =20
> WCPU CPU COMMAND
> > 5071 nobody 101 0 43124K 35180K CPU2 2 0:07=20
> 14.89% 14.89% httpd
> > 14409 nobody 4 0 43940K 36076K sbwait 0 0:01 =20
> 1.22% 1.22% httpd
> > 95515 nobody 4 0 39892K 32188K sbwait 1 0:08 =20
> 0.29% 0.29% httpd
>=20
> Try hitting 'S'. Perhaps the system spends too much time in=20
> system threads (i.e. the "syncer") :)
>=20
I think TOP and load averages are no longer accurate on FBSD 5.x and 6.x =
with SMP kernel. As far as I've seen. Load averages hit sometimes 8.0 =
without a noticable degradation in performance.
This is one TOP that freaked me out, notice Idle CPU is 70% while the =
process is showing it is using 99% of CPU. systat draws more accurate =
picture, however, load average is still useless as far as performance =
monitoring :
last pid: 10174; load averages: 1.63, 1.44, 1.20 =
up 4+00:25:19 00:39:20
169 processes: 2 running, 166 sleeping, 1 zombie
CPU states: 25.8% user, 0.0% nice, 0.7% system, 0.1% interrupt, 73.4% =
idle
Mem: 1316M Active, 1445M Inact, 297M Wired, 127M Cache, 112M Buf, 79M =
Free
Swap: 8762M Total, 2096K Used, 8760M Free
PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU CPU =
COMMAND
13362 root 111 0 36444K 34196K CPU3 3 50:06 98.88% 98.88% =
perl5.8.7
90391 root 96 0 27356K 26236K select 2 0:06 0.54% 0.54% =
perl5.8.7
79619 nobody 4 0 209M 84640K sbwait 1 0:09 0.39% 0.39% =
httpd
10161 root 97 0 6712K 4752K select 2 0:00 1.40% 0.20% =
exim-4.62-0
79649 nobody 20 0 210M 84464K lockf 0 0:06 0.15% 0.15% =
httpd
10158 mailnull 4 0 6760K 3992K sbwait 2 0:00 0.81% 0.15% =
exim-4.62-0
79654 nobody 4 0 208M 68660K sbwait 0 0:08 0.05% 0.05% =
httpd
79660 nobody 4 0 208M 58144K sbwait 0 0:06 0.05% 0.05% =
httpd
10170 sshd 117 0 4768K 2052K select 0 0:00 1.00% 0.05% sshd
1123 mysql 96 0 346M 214M select 2 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 3 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 3 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 2 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 0 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 2 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 1 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 0 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 0 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 3 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 3 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 0 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 1 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 2 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 1 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 1 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 0 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 0 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 2 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 1 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 0 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 2 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 0 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 1 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 0 114:48 0.00% 0.00% =
mysqld
1123 mysql 20 0 346M 214M kserel 1 114:48 0.00% 0.00% =
mysqld
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