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From: Don Bowman <don@sandvine.com>
To: 'Mike Tancsa' <mike@sentex.net>, Don Bowman <don@sandvine.com>
Date: Sun, 29 Feb 2004 20:44:56 -0500
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cc: freebsd-hackers@freebsd.org
Subject: RE: em0, polling performance, P4 2.8ghz FSB 800mhz
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From: Mike Tancsa [mailto:mike@sentex.net]
> 
> On Sat, 28 Feb 2004 23:17:44 -0500, in sentex.lists.freebsd.hackers >
> >If you want to spend more time in kernel, perhaps change
> >
> >I might have HZ @ 2500 as well.
> 
> Hi,
> 	Just curious as to the reasoning behind that ?

@ high packet rates, you don't have enough DMA
queues available to the em driver, and will drop.
increasing the number of dma buffers will cause
problems with cache occupancy. Increasing the HZ
doesn't have a huge cost.