Date: Sat, 14 Jan 2006 00:21:17 -0500 From: Kris Kennaway <kris@obsecurity.org> To: green@FreeBSD.org, current@FreeBSD.org Subject: Extreme contigmalloc() slowness with mpt driver Message-ID: <20060114052117.GA16773@xor.obsecurity.org>
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I have an amd64 machine with 16GB of RAM that takes ages to boot (~40
minutes on 7.0). This is because the mpt driver takes 20 minutes to
attach (with 2 instances). This in turn is because the following code
from dev/mpt/mpt_pci.c:mpt_dma_mem_alloc() takes about 5 seconds to
execute, and it is run 256 times in a loop:
error = bus_dmamap_create(mpt->buffer_dmat, 0, &req->dmap);
When I set vm.old_contigmalloc=1, the system boots without delay.
This points to a bug in contigmalloc.
Kris
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