[lkml]   [2007]   [Jun]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [PATCH] x86-64: disable the GART before allocate aperture
    On Saturday 23 June 2007 00:19:51 Alan Cox wrote:
    > > YH do you think you can look at simply reserving a portion of the iommu?
    > > And having the kexec on panic kernel use the reserved portion?
    > How about simply reserving all of it for the base kernel and using soft
    > iommu for the panic kernel, its hardly high performance criticial at this
    > point.

    The kdump kernel should be normally all <4GB anyways. You won't
    need any IOMMU for its IO unless you O_DIRECT/sendfile out of /proc/kcore.
    Just don't do that (but I suspect it won't work anyways)

    If it's not then swiotlb will also not work because it won't get
    any memory <4GB.

    But I doubt this was YH's problem - the panic kernel memory
    is always reserved and there shouldn't be any ongoing DMAs in this
    area anyways. And what happens outside the kdump kernel shouldn't matter.

    I suspect he rather saw problems with non kdump kexec where we
    can just shut down the GART properly beforehand.

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2007-06-23 02:17    [W:0.018 / U:14.024 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site