Re: [gentoo-user] top - 99.9% wa? What's 'wa'?
On 9/23/05, Neil Bothwick [EMAIL PROTECTED] wrote: On Thu, 22 Sep 2005 17:52:17 -0700, Mark Knecht wrote: It appears to me that when the screensaver burns up that much horsepower, whether it's CPU+Nice or CPU+Nice+Waiting, then mythbackend is having trouble. Why are you running a screensaver on a server? ;-) LOL! Ah, life is never that simple is it my friend? ;) Dragonfly is my wife's desktop machine. It sits in our family room and is fairly close to the media center so it got drafted as the mythbackend machine. It has the two PVR cards for capturing video and a 160GB drive, but a good chunk of the drive is storing our CD collection. 750CDs, approximately 50GB. In the end there wasn't enough video storage left on that drive (about 40 hours) to make everyone happy so Myth's video storage is across the network on an NFS mount. Clearly the screensaver runs because it's used mainly as her main desktop but is also a server for Myth. Myth14 is a Pundit-R. It only does MythTV and sits in the Media Center stack of receivers, amps, cable boxes, etc. Unfortunately the Pundit-R's are too small to cleanly accept a PVR card. You will read stories about people managing to get one in, but I didn;t feel like screwing up my cards so I didn't got that way. Further the PVR cards get a bit hot and I'm not confident of the cooling in this boxes so the machine is currently only a Myth frontend box for viewing on the TV. This was the 4th Pundit-R I built so in this one I put a 250GB drive even though Gentoo/MythTV only take up about 3GB. There is a 240GB partition on this machine for video storage which is exported with NFS for Dragonfly to mount. So... Dragonfly is a desktop but acts as the Myth backend server Myth14 is a Mythfrontend but acts as an NFS server Life is never that simple... ;-) - Mark -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] top - 99.9% wa? What's 'wa'?
DMA is essentially the AVOIDANCE of using the CPU for I/O. The CPU makes a few calls to the chipset (in the case of ATA DMA), and the rest happens around the processor, not threw it. Jason It's described in the vmstat man page. You're supposed to be clairvoyant about these things and know that virtual memory stats is where cpu time is described. :) It's Time spent waiting for IO. The cpu can't do anything until IO is completed - typically this is some kind of DMA transfer. -- gentoo-user@gentoo.org mailing list
[gentoo-user] top - 99.9% wa? What's 'wa'?
Hi, I'm looking at this mythbackend server machine using top. Sometimes the CPU usage goes to essentially 100%, but only in the 'wa' section. What is 'wa'? I searched through the man page but didn't see anything about this. I'm suspecting that this machine has stopped being able to keep up with MythTV due to something using up CPU time. I found that one of my wife's screensavers (Fireworks) was using 70-90% CPU so I've turned that off and things seem much better. Now when watching top I never see anything using more than a few %, but this 'wa' thing persists. top - 14:51:47 up 4:19, 3 users, load average: 1.75, 1.88, 1.58 Tasks: 91 total, 2 running, 88 sleeping, 0 stopped, 1 zombie Cpu(s): 0.3% us, 0.3% sy, 0.0% ni, 0.0% id, 97.7% wa, 0.0% hi, 1.7% si Mem:499052k total, 493560k used, 5492k free, 3140k buffers Swap: 1052216k total, 368k used, 1051848k free, 342352k cached Thanks, Mark -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] top - 99.9% wa? What's 'wa'?
On Thu, 22 Sep 2005 14:59:55 -0700, Mark Knecht wrote: I'm looking at this mythbackend server machine using top. Sometimes the CPU usage goes to essentially 100%, but only in the 'wa' section. What is 'wa'? I searched through the man page but didn't see anything about this. Waiting. I usually see it go up during heavy disk I/O. -- Neil Bothwick You know it's going to be a bad day when you forget your new password. pgpmb3imaDAE9.pgp Description: PGP signature
Re: [gentoo-user] top - 99.9% wa? What's 'wa'?
On 9/22/05, Neil Bothwick [EMAIL PROTECTED] wrote: On Thu, 22 Sep 2005 14:59:55 -0700, Mark Knecht wrote: I'm looking at this mythbackend server machine using top. Sometimes the CPU usage goes to essentially 100%, but only in the 'wa' section. What is 'wa'? I searched through the man page but didn't see anything about this. Waiting. I usually see it go up during heavy disk I/O. Thanks Neil. That's helpful. Seems strange to me that I saw a lot of 'waiting' while this one 'fireworkx' screensaver even in xscreensaver-demo. Basically I'm getting a pretty consistent 12 % CPU 42% Nice 40% Waiting It appears to me that when the screensaver burns up that much horsepower, whether it's CPU+Nice or CPU+Nice+Waiting, then mythbackend is having trouble. My first test of recording something new but making sure a low power screensaver was in effect worked just fine. Again, thanks for the info. - Mark -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] top - 99.9% wa? What's 'wa'?
On Thu, 22 Sep 2005 14:59:55 -0700 Mark Knecht [EMAIL PROTECTED] wrote: Hi, I'm looking at this mythbackend server machine using top. Sometimes the CPU usage goes to essentially 100%, but only in the 'wa' section. What is 'wa'? I searched through the man page but didn't see anything about this. It's described in the vmstat man page. You're supposed to be clairvoyant about these things and know that virtual memory stats is where cpu time is described. :) It's Time spent waiting for IO. The cpu can't do anything until IO is completed - typically this is some kind of DMA transfer. I'm suspecting that this machine has stopped being able to keep up with MythTV due to something using up CPU time. I found that one of my wife's screensavers (Fireworks) was using 70-90% CPU so I've turned that off and things seem much better. Now when watching top I never see anything using more than a few %, but this 'wa' thing persists. Nope, it's just slow doing IO - bottleneck in either disk to memory, video to memory, or memory to network. top - 14:51:47 up 4:19, 3 users, load average: 1.75, 1.88, 1.58 Tasks: 91 total, 2 running, 88 sleeping, 0 stopped, 1 zombie Cpu(s): 0.3% us, 0.3% sy, 0.0% ni, 0.0% id, 97.7% wa, 0.0% hi, 1.7% si Mem:499052k total, 493560k used, 5492k free, 3140k buffers Swap: 1052216k total, 368k used, 1051848k free, 342352k cached Looks like it might help a bit to increase the systems main memory to 1 GB. It'll eliminate the swapping and will increase the available in-memory filesystem buffering. Bob - -- gentoo-user@gentoo.org mailing list
