[PATCH 0/3 v3] Fix kdump failures with crashkernel=high
bp at alien8.de
Fri Jun 5 06:27:36 PDT 2015
On Fri, Jun 05, 2015 at 12:29:59PM +0200, Joerg Roedel wrote:
> * Rebased to v4.1-rc6
> * Updated changelogs as requested and added outcome of
> previous discussions
> * Added more Acked-bys
> * Updated comments based on feedback from Konrad
> * Added Acked-bys
> * Rebased to v3.19-rc3
> here is a patch-set to fix failed kdump kernel boots when
> the systems was booted with crashkernel=X,high. On those
> systems the kernel allocates only 72MiB of low-memory for
> DMA buffers, which showed to be too low on some systems.
> The problem is that 64MiB of the low-memory is allocated by
> swiotlb, leaving 8MB for the page-allocator. But swiotlb
> tries to allocate DMA memory from the page-allocator first,
> which fails pretty fast in the boot sequence, causing
> warnings. This patch-set removes these warnings.
> But even the 64MiB for swiotlb are eaten up on some systems,
> so that the default of low-memory allocated for the
> crash-kernel is increase from 72MB to 256MB (only changing
> the defaults, can still be overwritten by crashkernel=X,low).
> This number comes from experiments on the affected systems,
> 128MiB low-memory was still not enough there, thus I set the
> value to 256MiB to fix the issues.
> Any feedback appreciated.
> Joerg Roedel (3):
> swiotlb: Warn on allocation failure in swiotlb_alloc_coherent
> x86, swiotlb: Try coherent allocations with __GFP_NOWARN
> x86, crash: Allocate enough low-mem when crashkernel=high
> arch/x86/kernel/pci-swiotlb.c | 7 +++++++
> arch/x86/kernel/setup.c | 5 ++++-
> lib/swiotlb.c | 11 +++++++++--
> 3 files changed, 20 insertions(+), 3 deletions(-)
Looks simple enough, all applied, thanks.
hpa, Ingo, any concerns?
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