Date: Sun, 18 Jun 1995 19:46:25 +1000 From: Bruce Evans <bde@zeta.org.au> To: hsu@clinet.fi Cc: current@freebsd.org Subject: Re: kern/528: interrupt-level buffer overflows Message-ID: <199506180946.TAA22668@godzilla.zeta.org.au>
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> Kernel spits out lot of these >Jun 18 05:14:47 pommi /kernel: sio1: 119 more interrupt-level buffer over >flows (total 3642) >Jun 18 05:14:47 pommi /kernel: sio1: 119 more interrupt-level buffer overflows ( >total 3642) For this to happen, softclock() must sometimes be delayed for a long time several clock ticks (about 3 clock ticks for 119 characters at 38400 bps and about (256 - 38) / 38 clock ticks for filling up the 256 character buffer before that. > It also very easily reboots when lots of PPP load exits. I don't know what causes that. > Low tcp performance hints that it is loosing lots of data. All the data reported in the buffer overflow messages is lost. >>Fix: > > I think this feature has already been discussed; grepping > 'interrupt-level' from FAQ's didn't help. If this is a feature > which can be worked around, this might be a doc-bug? However, I Use hardware handshaking. > find it curous how a 386-16 could be too slow to respond for a 38400 > bps link? I've heard that some systems 20 times as fast as a 386/16 are too slow for a 38400 bps link. Bruce
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