amd64/87977 : [busdma] [panic] amd64 busdma dflt_lock called (by ata) if physmem>4G

Attila Nagy bra at
Tue Dec 27 12:50:08 PST 2005

The following reply was made to PR amd64/87977; it has been noted by GNATS.

From: Attila Nagy <bra at>
To: Thomas Hurst <tom at>
Cc: freebsd-amd64 at,  bug-followup at
Subject: Re: amd64/87977 : [busdma] [panic] amd64 busdma dflt_lock called
 (by ata) if physmem>4G
Date: Tue, 27 Dec 2005 21:41:35 +0100

 Thomas Hurst wrote:
 >>I believe this is fixed in CURRENT. On 6-STABLE you can set hw.physmem
 >>to use a smaller amount of memory or switch to the ata driver before
 > Thanks for the pointer.  I grabbed sys/dev/ata and sys/sys/ata.h off
 > my CURRENT laptop and popped it on my RELENG_6 Opteron and it appears
 > to work fine with all 4G -- I can pull data off all 4 disks at >250M/s
 > without trouble when I could previously not even get past mounting
 > filesystems.
 > Hope to see this merged before too long, but for now at least this pr is
 > a little bit more useful :)
 Good to hear that, thanks.
 According to Soren the whole ATA driver will be merged soon.
 Attila Nagy                                   e-mail: Attila.Nagy at
 Free Software Network (FSN.HU)                 phone: +3630 306 6758

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