On Thu, 5 Jan 2006, Helmut Toplitzer wrote: > This is not funny anymore:
> =========================== REBOOT ===================================== Which HCD modules are loaded when you reboot? Only uhci-hcd? > # hdparm -t /dev/hda > > /dev/hda: > Timing buffered disk reads: 44 MB in 3.13 seconds = 14.05 MB/sec > # modprobe ehci-hcd > ========= CPU GOES TO 100% ============================================= > # hdparm -t /dev/hda > > /dev/hda: > Timing buffered disk reads: 172 MB in 3.02 seconds = 56.87 MB/sec So loading ehci-hcd _improves_ disk performance. > # rmmod ehci-hcd > # hdparm -t /dev/hda > > /dev/hda: > Timing buffered disk reads: 170 MB in 3.01 seconds = 56.44 MB/sec And then unloading it doesn't reduce performance. How's that for service? :-) The difference between this state and the original state is a mystery, however. > # /etc/init.d/lirc stop > Stopping lirc daemon: lircmd lircd. What made you think of stopping lircd? > ========== CPU GOES BACK TO NORMAL (<<10%) ============================= > ~# hdparm -t /dev/hda > > /dev/hda: > Timing buffered disk reads: 104 MB in 3.02 seconds = 34.39 MB/sec Stopping it did reduce disk performance. Odd. > =========================== REBOOT ===================================== > # hdparm -t /dev/hda > > /dev/hda: > Timing buffered disk reads: 44 MB in 3.06 seconds = 14.40 MB/sec > # rmmod uhci-hcd > ========= CPU GOES TO 100% ============================================= > # hdparm -t /dev/hda > > /dev/hda: > Timing buffered disk reads: 172 MB in 3.02 seconds = 56.87 MB/sec Unloading uhci-hcd also improved performance. Is this because you have a high-speed USB device that is controlled by uhci-hcd only when ehci-hcd isn't loaded? > # /etc/init.d/lirc stop > Stopping lirc daemon: lircmd lircd. > ========= CPU GOES BACK TO NORMAL (<<10%) ============================== > # hdparm -t /dev/hda > > /dev/hda: > Timing buffered disk reads: 112 MB in 3.02 seconds = 37.08 MB/sec Got to admit, I don't understand why stopping lircd should reduce your disk performance. Does restarting it cause the performance to improve again? Alan Stern ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
