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 - -- [email protected] mailing list
