busdma dflt_lock on amd64 > 4 GB

Attila Nagy bra at fsn.hu
Mon Nov 7 19:22:44 PST 2005

Scott Long wrote:
>> I also wonder if allocating bounce pages on <=4G configurations is 
>> really needed/useful? There are probably situations where this is 
>> needed, but I'm not sure I understand why.
> It sounds like the only real bug in busdma is that it gets confused by 
> ALLOCNOW and doesn't allow enough pages to be allocated when 
> bus_dmamap_create() is called.  I'll look into this.
It seems that this is the last post in this topic. I have an HP DL145G2 
with 4 GB RAM (dual AMD64) and with two SATA disks, on which I created a 
mirror (gmirror).

It dies with this in the moment I issue gmirror insert ad6 on a degraded 
Setting hw.physmem below 4G solves the issue.

The interesting stuff is that the machine worked with 4G with earlier 
kernels (6.0-BETA5 I think).

What has changed?

Attila Nagy                                   e-mail: Attila.Nagy at fsn.hu
Free Software Network (FSN.HU)                 phone: +3630 306 6758
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