Subject: Re: ioflush is taking excessive cycles on a big-memory machine
To: NetBSD Kernel Technical Discussion List <>
From: Chuck Silvers <>
List: tech-kern
Date: 04/10/2005 11:58:01
On Mon, Apr 04, 2005 at 07:50:52PM -0400, Greg A. Woods wrote:
> Something I've done has got my big AlphaServer (with 16GB of RAM) into a
> state where the [ioflush] thread is chewing up a minimum of "25%"
> (according to 'top') of the (a?) CPU, and at times it jumps up to 50% or
> higher.  This also makes the machine very sluggish -- just typing to the
> command-line can have multi-second lag between keystroke and echo (with
> command-line editing).

what version is your kernel?  the 3.x branch should behave much better
than 2.x kernels did, some fixes went into -current about 8 months ago
that should have dramatically reduced the CPU usage of ioflush.