Re: BUG: Kernel Panic: kernel-2.6.0-test9-bk21 for alpha in scsicontext ll_rw_blk.c

From: Thomas Steudten
Date: Mon Nov 17 2003 - 16:35:14 EST


On http://steudten.com/alpha/perf.php4 you can read:
See prefetch section:
The Alpha 21264 initiates a prefetch operation by executing one of the load instructions as summarized in the table below. Note that the destination register is R31 or F31. When used as a source register, R31 and F31 return integer zero and floating point zero, respectively. When used as a destination register as shown below, R31 and F31 denote the purpose of these instructions as a prefetch operation. Earlier Alpha implementations ignore these instructions. Some care must be taken as a prefetch with an invalid address must be dismissed by firmware and a prefetch can cause an alignment trap.

Tom


Falk Hueffner wrote:

Thomas Steudten <alpha@xxxxxxxxxxxx> writes:


-> 0xfffffc0000476cb8 <__make_request+152>: lds $f31,0(t2)


The kernel is stupid, this is a prefetch, it should be totally ignored
if it is faulty. This is already handled for userspace accesses
IIRC... (I wonder why the PALcode doesn't already do that. Oh well.)


--
Tom

LINUX user since kernel 0.99.x 1994.
RPM Alpha packages at http://alpha.steudten.com/packages
Want to know what S.u.S.E 1995 cdrom-set contains?


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