lkml.org 
[lkml]   [2015]   [Jan]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Subject[PATCH 0/3 v2] Fix kdump failures with crashkernel=high
Date
v1->v2:

* Updated comments based on feedback from Konrad
* Added Acked-bys
* Rebased to v3.19-rc3

Hi,

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.

Thanks,

Joerg

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 | 8 ++++++++
arch/x86/kernel/setup.c | 5 ++++-
lib/swiotlb.c | 11 +++++++++--
3 files changed, 21 insertions(+), 3 deletions(-)

--
1.9.1

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 | 8 ++++++++
arch/x86/kernel/setup.c | 5 ++++-
lib/swiotlb.c | 11 +++++++++--
3 files changed, 21 insertions(+), 3 deletions(-)

--
1.9.1



\
 
 \ /
  Last update: 2015-01-06 16:01    [W:0.139 / U:7.948 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site