Messages in this thread | | | Date | Wed, 22 Jul 2015 12:11:33 +0200 | From | Joerg Roedel <> | Subject | Re: [PATCH v2] Do not reserve crashkernel high memory if crashkernel low memory reserving failed |
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On Tue, Jul 21, 2015 at 12:22:53PM -0700, Yinghai Lu wrote: > On Tue, Jul 21, 2015 at 1:58 AM, Baoquan He <bhe@redhat.com> wrote: > > > Maybe system which don't need low memory is rare, only for testing? > > No, it is not rare. > > All recent intel based systems with iommu support does not need low.
All Intel-IOMMU systems have the iommu disabled by default (at least that is the default in most distros). So low memory is definitly needed by those systems too.
> that reserve 256M low always. and those 256M get wasted. > > That commit should only be used to workaround some systems that > have partial iommu support.
We currently lack the infrastructure for that, but I am happy to review patches. How about letting subsystems announce their need for low crash-kernel memory and allocate based on that?
The subsystems (like iommu or swiotlb code, for example) could even announce how much memory they need and we base our allocation on that.
Joerg
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