lkml.org 
[lkml]   [2013]   [Mar]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] x86, kdump: Set crashkernel_low automatically
    On Sun, Mar 10, 2013 at 09:56:57PM -0700, Yinghai Lu wrote:
    > Current code does not set low range for crashkernel if the user
    > does not specify that.
    >
    > That cause regressions on system that does not support intel_iommu
    > properly.
    >
    > Chao said that his system does work well on 3.8 without extra parameter.
    > even iommu does not work with kdump.
    >
    > Set crashkernel_low automatically if the user does not specify that.
    >
    > For system that does support IOMMU with kdump properly, user could
    > specify crashkernel_low=0 to save that 72M low ram.
    >

    Hi Yinghai,

    Had a question about crashkernel_auto_low. So this is the amount of
    memory rerved under 4G. I am not very clear about the semantics here.

    So by default memory wil always come from areas above 4G (when
    crashkernel=X specified) and if user needs reserveation in lower memory
    area, it needs to be sepcified explicitly using crashkernel_low?

    But will that not break the case of exising bzImage which are 32bit.
    They currently work if I specify crashkernel=256M. Now suddenly memory
    will come from higher addresses and 32bit bzImage can't be loaded there.
    Or I understood the syntax part wrong.

    P.S. Explanation in kernel-parameters.txt is really short. Can you please
    add some explanation in kdump.txt to clarify how crashkernel_low
    is supposed to be used.

    Thanks
    Vivek


    \
     
     \ /
      Last update: 2013-03-11 16:21    [W:2.792 / U:0.056 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site