svn commit: r212061 - head/sys/dev/bge
kabaev at gmail.com
Sat Sep 4 05:00:30 UTC 2010
On Tue, 31 Aug 2010 17:33:48 +0000 (UTC)
Pyun YongHyeon <yongari at FreeBSD.org> wrote:
> Author: yongari
> Date: Tue Aug 31 17:33:48 2010
> New Revision: 212061
> URL: http://svn.freebsd.org/changeset/base/212061
> Split common parent DMA tag into ring DMA tag and TX/RX mbuf DMA
> tag. All controllers that are not BCM5755 or higher have 4GB
> boundary DMA bug. Previously bge(4) used 32bit DMA address to
> workaround the bug(r199670). However this caused the use of bounce
> buffers such that it resulted in poor performance for systems which
> have more than 4GB memory. Because bus_dma(9) honors boundary
> restriction requirement of DMA tag for dynamic buffers, having a
> separate TX/RX mbuf DMA tag will greatly reduce the possibility of
> using bounce buffers. For DMA buffers allocated with
> bus_dmamem_alloc(9), now bge(4) explicitly checks whether the
> requested memory region crossed the boundary or not.
> With this change, only the DMA buffer that crossed the boundary
> will use 32bit DMA address. Other DMA buffers are not affected as
> separate DMA tag is created for each DMA buffer.
> Even if 32bit DMA address space is used for a buffer, the chance to
> use bounce buffer is still very low as the size of buffer is small.
> This change should eliminate most usage of bounce buffers on
> systems that have more than 4GB memory.
> More correct fix would be teaching bus_dma(9) to honor boundary
> restriction for buffers created with bus_dmamem_alloc(9) but it
> seems that is not easy.
> While I'm here cleanup bge_dma_map_addr() and remove unnecessary
> member variables in bge_dmamap_arg structure.
> Tested by: marcel
with this commit my AMD64 machine reliably reboots after several
minutes of uptime. Attempting cvs update of ports from repository
located on NFS server seems to make it happen sooner.
bge0: <Broadcom NetXtreme Gigabit Ethernet Controller, ASIC rev.
0x001002> mem 0xfd8f0000-0xfd8fffff irq 24 at device 9.0 on pci2
miibus0: <MII bus> on bge0
brgphy0: <BCM5703 10/100/1000baseTX PHY> PHY 1 on miibus0
brgphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT,
bge0: Ethernet address: 00:e0:81:28:24:e7
Booting kernel tree from just before this commit makes everything work
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