Messages in this thread | | | Date | Tue, 16 Sep 2014 10:31:22 -0400 | From | Neil Horman <> | Subject | Re: bisected regression: 3c59x corrupts packets in 3.17-rc5 |
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On Tue, Sep 16, 2014 at 01:32:31PM +0300, Meelis Roos wrote: > [ Fixed Steffen Klasserts bouncing email address as per the bounce message ] > > > > Somewhere between 3.17.0-rc3 and 3.17.0-rc5 I started seeing dropped ssh > > > connections to a couple of test servers with dual AthlonMP (32-bit) and > > > 3C90x family of NICs (3Com Corporation 3c980-C 10/100baseTX NIC > > > [Python-T] (rev 78) in one server and 3Com Corporation 3c905C-TX/TX-M > > > [Tornado] (rev 78) in the other server). Bisect leads to the following > > > commit: > > > > > > 98ea232cf63961fad734cc8c5e07e8915ec73073 is the first bad commit > > > commit 98ea232cf63961fad734cc8c5e07e8915ec73073 > > > Author: Neil Horman <nhorman@tuxdriver.com> > > > Date: Thu Sep 4 06:13:38 2014 -0400 > > > > > > 3c59x: avoid panic in boomerang_start_xmit when finding page address: > > > ... > > > > > I'm guessing the above change has uncovered another bug, mostly likely an > > exhaustion of dma space on your system. Nothing in the transmit path there does > > any error checking for successful dma mapping, which it really should. I'd be > > willing to be that any dma mapping error leads to a leak in the mapping table. > > Does your system have an iommu, or does it use swiotlb? If its the latter, can > > you increase the swiotlb table space and see if that relieves the problem? In > > the interim, I'll start adding some error checking to the transmit path. > > # CONFIG_IOMMU_SUPPORT is not set > > nothing matching iommu or iotlb in dmesg. I thought the system does not > have any - K7 CPUs and AMD 760MP chipset with normal AGP gart. > > [ 3.763519] agpgart-amdk7 0000:00:00.0: AMD 760MP chipset > [ 3.782995] agpgart-amdk7 0000:00:00.0: AGP aperture is 64M @ 0xf8000000 > Then I think you are likely very lmiited in how much DMA memory you can map (may be limited to ZONE_DMA), which is likely from where this problem is stemming. Try adding swiotlb= setup to the kernel command line and play with the size to see if you can avoid the problem. I also have a patch I'm sending you to test.
Neil
> -- > Meelis Roos (mroos@linux.ee) > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
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