Date: Fri, 13 Jan 2006 21:53:47 -0800 From: Steve Kargl <sgk@troutmask.apl.washington.edu> To: Kris Kennaway <kris@obsecurity.org> Cc: current@freebsd.org Subject: Re: Extreme contigmalloc() slowness with mpt driver Message-ID: <20060114055347.GA45580@troutmask.apl.washington.edu> In-Reply-To: <20060114052117.GA16773@xor.obsecurity.org> References: <20060114052117.GA16773@xor.obsecurity.org>
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On Sat, Jan 14, 2006 at 12:21:17AM -0500, Kris Kennaway wrote: > 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. > This is probably related to my recent reports of extremely slow probing of fxp0. I have 12 GB on a Tyan K8S Pro and fxp0 takes on the order of 7 minutes to probe. -- Steve
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