From: Rick S. <nec...@gm...> - 2006-08-17 16:54:21
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I was wondering why this phase of the boot process is so slow. Is there some way I can speed it up? If there is some configuration I can tweak to skip this step, that would be great, if it would require changing a lot of kernel source or what-not, then just tell me that also, and I will live with it. Any explanation as to why this is so slow though would be greatly appreciated. -- Rick nec...@gm... |
From: Mattia D. <mal...@li...> - 2006-08-17 18:11:20
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On Thu, Aug 17, 2006 at 12:54:18PM -0400, Rick Spillane wrote: > I was wondering why this phase of the boot process is so slow. Is > there some way I can speed it up? If there is some configuration I can > tweak to skip this step, that would be great, if it would require > changing a lot of kernel source or what-not, then just tell me that > also, and I will live with it. Any explanation as to why this is so > slow though would be greatly appreciated. I don't know and I'm wondering the same... As far as I can tell debian sid has this problem mainly, I'm running woody (oh! this didn't have udev yet), sarge and an up-to-date gentoo that don't show the same slowness. Any clue anybody? BTW, you can get rid of udev by using a static /dev -- mattia :wq! |
From: Jeff D. <jd...@ad...> - 2006-08-17 20:16:50
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On Thu, Aug 17, 2006 at 12:54:18PM -0400, Rick Spillane wrote: > I was wondering why this phase of the boot process is so slow. Is > there some way I can speed it up? If there is some configuration I can > tweak to skip this step, that would be great, if it would require > changing a lot of kernel source or what-not, then just tell me that > also, and I will live with it. Any explanation as to why this is so > slow though would be greatly appreciated. It creates a hell of a lot of short-lived processes. Process creation is slow for UML, so this makes this part of the boot particularly slow. I do have a patch in my tree which speeds up fork by removing the signal delivery that was used to initialize the new kernel stack. This gives a speedup on the order of 5% on fork, which you probably wouldn't notice watching a boot. The next thing I'm going to look at is avoiding the page table scan that happens before the new process starts up. That has a better chance of being noticable. Jeff |
From: Nix <ni...@es...> - 2006-08-27 20:11:18
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On Thu, 17 Aug 2006, Jeff Dike wrote: > On Thu, Aug 17, 2006 at 12:54:18PM -0400, Rick Spillane wrote: >> I was wondering why this phase of the boot process is so slow. Is >> there some way I can speed it up? If there is some configuration I can >> tweak to skip this step, that would be great, if it would require >> changing a lot of kernel source or what-not, then just tell me that >> also, and I will live with it. Any explanation as to why this is so >> slow though would be greatly appreciated. > > It creates a hell of a lot of short-lived processes. Process creation > is slow for UML, so this makes this part of the boot particularly > slow. If you use udevtrigger from udev 088 or higher instead of the shell script stanza, this should no longer be a problem. -- `In typical emacs fashion, it is both absurdly ornate and still not really what one wanted.' --- jdev |