Messages in this thread | | | Date | Sat, 8 Apr 2006 18:27:21 +0200 | From | "Alessandro Suardi" <> | Subject | Re: 40% IDE performance regression going from FC3 to FC5 with same kernel |
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On 4/8/06, Arjan van de Ven <arjan@infradead.org> wrote: > > > Just for the record - no, even rebuilding same kernel with same GCC > > (3.4.4) under FC5, disk performance is much slower than FC3 - > > according to hdparm _and_ dd tests. > > what happens if you kill hald and other inotify using animals?
Thanks Arjan for looking into this.
Stopping hald brings hdparm from 18.5MB/s to 20MB/s, which is indeed a noticeable improvement, though still far from the FC3 performance. I'm unsure what else can be stopped however from this process list:
[root@donkey init.d]# ps ax PID TTY STAT TIME COMMAND 1 ? S 0:00 init [3] 2 ? SN 0:00 [ksoftirqd/0] 3 ? S 0:00 [watchdog/0] 4 ? S< 0:00 [events/0] 5 ? S< 0:00 [khelper] 6 ? S< 0:00 [kthread] 8 ? S< 0:00 [kblockd/0] 11 ? S< 0:00 [khubd] 40 ? S 0:00 [kapmd] 72 ? S 0:00 [pdflush] 73 ? S 0:00 [pdflush] 74 ? S 0:00 [kswapd0] 75 ? S< 0:00 [aio/0] 76 ? S 0:00 [cifsoplockd] 77 ? S 0:00 [cifsdnotifyd] 153 ? S< 0:00 [kseriod] 186 ? S 0:00 [kedac] 199 ? S 0:00 [kjournald] 274 ? S<s 0:00 /sbin/udevd -d 346 ? S< 0:00 [kpsmoused] 781 ? S< 0:00 [scsi_eh_0] 782 ? S< 0:00 [usb-storage] 836 ? S 0:00 [kjournald] 838 ? S 0:00 [kjournald] 840 ? S 0:00 [kjournald] 842 ? S 0:00 [kjournald] 844 ? S 0:00 [kjournald] 1170 ? Ss 0:00 syslogd -m 0 1173 ? Ss 0:00 klogd -x 1197 ? Ss 0:00 portmap 1216 ? Ss 0:00 rpc.statd 1295 ? Ss 0:00 /usr/sbin/apmd -p 10 -w 5 -W -P /etc/sysconfig/apm-sc 1440 ? Ss 0:00 cupsd 1480 ? Ss 0:00 /usr/sbin/sshd 1504 ? Ss 0:00 sendmail: accepting connections 1514 ? Ss 0:00 sendmail: Queue runner@01:00:00 for /var/spool/client 1524 ? Ss 0:00 gpm -m /dev/input/mice -t exps2 1533 ? Ss 0:00 crond 1582 ? Ss 0:00 /usr/sbin/atd 1662 tty1 Ss+ 0:00 /sbin/mingetty tty1 1663 tty2 Ss+ 0:00 /sbin/mingetty tty2 1666 tty3 Ss+ 0:00 /sbin/mingetty tty3 1669 tty4 Ss+ 0:00 /sbin/mingetty tty4 1672 tty5 Ss+ 0:00 /sbin/mingetty tty5 1703 tty6 Ss+ 0:00 /sbin/mingetty tty6 1718 ? Ss 0:00 sshd: root@pts/0 1742 pts/0 Ss 0:00 -bash 1859 pts/0 R+ 0:00 ps ax
strace shows read() system time practically identical around 1.3s, hence I ran a ltrace comparison, which shows this:
FC3:
[root@donkey ~]# ltrace -c dd if=/dev/hdb of=/dev/null skip=400 bs=1024k count=200 200+0 records in 200+0 records out % time seconds usecs/call calls function ------ ----------- ----------- --------- -------------------- 99.86 14.597554 72987 200 read 0.10 0.015150 75 200 write 0.01 0.000947 473 2 dcgettext 0.01 0.000871 435 2 fprintf 0.00 0.000634 634 1 setlocale
FC5:
[root@donkey ~]# ltrace -c dd if=/dev/hdb of=/dev/null skip=400 bs=1024k count=200 200+0 records in 200+0 records out 209715200 bytes (210 MB) copied, 9.49944 seconds, 22.1 MB/s % time seconds usecs/call calls function ------ ----------- ----------- --------- -------------------- 99.81 27.460675 137303 200 read 0.12 0.032411 32411 1 dcgettext 0.05 0.014069 70 200 write 0.00 0.000908 302 3 __fprintf_chk
FC5 rebooted, with hald stopped:
[root@donkey init.d]# ltrace -c dd if=/dev/hdb of=/dev/null skip=400 bs=1024k count=200 200+0 records in 200+0 records out 209715200 bytes (210 MB) copied, 8.83107 seconds, 23.7 MB/s % time seconds usecs/call calls function ------ ----------- ----------- --------- -------------------- 99.93 26.791861 133959 200 read 0.05 0.014154 70 200 write 0.00 0.000925 925 1 dcgettext 0.00 0.000856 285 3 __fprintf_chk
Note the usecs/call comparison for read()...
[Also note how the ltrace output is wrong in terms of absolute timing - approximately 3x the actual elapsed time]
Thanks,
--alessandro
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