[opensuse] nice and sluggishness
Hi guys, Just wondering. If I set a single process to have a nice value of -1, and the process does not use 100% CPU, why does it make the whole machine sluggish? I'm busy transferring video from VCR to my notebook. Mencoder is using between 60 and 80% CPU at any time, so performance is not an issue. But to avoid framedropping when I open or close something while working in the meantime, or to avoid disaster when updatedb kicks in, I set mencoder to be nice -1. Even though mencoder still only uses 60-80% CPU, everthing else is now sluggish - even the mouse movements are slow and jerky. Thanks Hans -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Mon, 2006-11-27 at 00:48 +0200, Hans du Plooy wrote:
Just wondering. If I set a single process to have a nice value of -1, and the process does not use 100% CPU, why does it make the whole machine sluggish?
I'm busy transferring video from VCR to my notebook. Mencoder is using between 60 and 80% CPU at any time, so performance is not an issue. But to avoid framedropping when I open or close something while working in the meantime, or to avoid disaster when updatedb kicks in, I set mencoder to be nice -1. Even though mencoder still only uses 60-80% CPU, everthing else is now sluggish - even the mouse movements are slow and jerky.
I should also add the the video goes to an external firewire drive, so there's no load on the notebook's hard drive. Hans -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Hans, On Sunday 26 November 2006 14:48, Hans du Plooy wrote:
Hi guys,
Just wondering. If I set a single process to have a nice value of -1, and the process does not use 100% CPU, why does it make the whole machine sluggish?
I'm busy transferring video from VCR to my notebook. Mencoder is using between 60 and 80% CPU at any time, so performance is not an issue. But to avoid framedropping when I open or close something while working in the meantime, or to avoid disaster when updatedb kicks in, I set mencoder to be nice -1. Even though mencoder still only uses 60-80% CPU, everthing else is now sluggish - even the mouse movements are slow and jerky.
There's more to what happens in a computer than CPU usage. I/O matters, too, as do interrupts (the mouse, like all I/O devices, being interrupt-driven). Probably it's I/O load that's slowing your system even when mencoder doesn't need all or even most of the CPU. In fact, I/O limits may be slowing mencoder, too. I'm not sure it will help, but you might want to familiarize yourself with "ionice." As the name suggests, it's the I/O counterpart to "nice," which addresses only CPU consumption. How many independent disk drives do you have? What bus do they use (i.e., SCSI, IDE or SATA)? What spindle RPMs do they use? Have you configured optimal DMA for all your high-throughput devices (disks and your video interface hardware, at the least)?
Thanks Hans
Randall Schulz -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Sun, 2006-11-26 at 15:12 -0800, Randall R Schulz wrote:
There's more to what happens in a computer than CPU usage. I/O matters, too, as do interrupts (the mouse, like all I/O devices, being interrupt-driven).
This is probably it, thanks!
Probably it's I/O load that's slowing your system even when mencoder doesn't need all or even most of the CPU. In fact, I/O limits may be slowing mencoder, too.
I sent another mail to the list just after the first one to address this. I'm sending the video directly to an external firewire disc. The usage on the disc is anyway not too high (I'm encoding on the fly). Even if I write to the notebook's disc, if I don't use nice it runs smoothly and I can still use the notebook. The only reason I use nice is to avoid the odd dropped frame.
I'm not sure it will help, but you might want to familiarize yourself with "ionice." As the name suggests, it's the I/O counterpart to "nice," which addresses only CPU consumption. I'm familiar with ionice - I tried that initially but it didn't make any difference. I supposed the disc usage is not high enough.
How many independent disk drives do you have? Two
What bus do they use (i.e., SCSI, IDE or SATA)? What spindle RPMs do they use? Have you configured optimal DMA for all your high-throughput devices (disks and your video interface hardware, at the least)? Notebook: IDE 5400rpm 8mb cache. DMA is on, but I didn't do anything extra - left it as SUSE configured, and it is performing quite well.
External: IDE 7200rpm 16mb cache, in a firewire enclosure. The KDE automount mounts it with "sync" so I remount it without sync, otherwise it is quite slow. Thanks Hans -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 The Monday 2006-11-27 at 09:41 +0200, Hans du Plooy wrote:
Even if I write to the notebook's disc, if I don't use nice it runs smoothly and I can still use the notebook. The only reason I use nice is to avoid the odd dropped frame.
You could try to recompile that program optimizing for speed, then. Maybe it has settings about real time, too. - -- Cheers, Carlos E. R. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) Comment: Made with pgp4pine 1.76 iD8DBQFFatXWtTMYHG2NR9URAnHDAKCSl2uoEpMi/7amUpFollxPMLgFYQCdFV6s asDipe8rzB27IlkOy4no7pk= =yHR6 -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Carlos E. R. a écrit :
You could try to recompile that program optimizing for speed, then. Maybe it has settings about real time, too.
may be get a look at RT kernels? by the way, I use dvgrab for dv download from camcorder to my ide disk and never have a frame loss (two years old computer) (dvgrab have a stop on frame loss feature) jdd -- http://www.dodin.net http://dodin.org/mediawiki/index.php/GPS_Lowrance_GO -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Mon, 2006-11-27 at 13:26 +0100, jdd wrote:
may be get a look at RT kernels? I'll look into that.
by the way, I use dvgrab for dv download from camcorder to my ide disk and never have a frame loss (two years old computer) (dvgrab have a stop on frame loss feature)
What kind of output do you get with dvgrab? Can dvgrab talk to a tv tuner? Thanks Hans -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
participants (4)
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Carlos E. R. -
Hans du Plooy -
jdd -
Randall R Schulz