korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-29 23:24:11 +08:00
Code Issues Packages Projects Releases Wiki Activity

arm64: kdump: Provide default size when crashkernel=Y,low is not specified

Browse Source 
Try to allocate at least 128 MiB low memory automatically for the case
that crashkernel=,high is explicitly specified, while crashkenrel=,low
is omitted. This allows users to focus more on the high memory
requirements of their business rather than the low memory requirements
of the crash kernel booting.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Acked-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20221116121044.1690-2-thunder.leizhen@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Zhen Lei 2022-11-16 20:10:43 +08:00 committed by Will Deacon
parent f0c4d9fc9c
commit a149cf00b1
2 changed files with 11 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
Documentation/admin-guide/kernel-parameters.txt
View File

@ -851,26 +851,23 @@
available.
It will be ignored if crashkernel=X is specified.
crashkernel=size[KMG],low
[KNL, X86-64] range under 4G. When crashkernel=X,high
[KNL, X86-64, ARM64] range under 4G. When crashkernel=X,high
is passed, kernel could allocate physical memory region
above 4G, that cause second kernel crash on system
that require some amount of low memory, e.g. swiotlb
requires at least 64M+32K low memory, also enough extra
low memory is needed to make sure DMA buffers for 32-bit
devices won't run out. Kernel would try to allocate
at least 256M below 4G automatically.
default size of memory below 4G automatically. The default
size is platform dependent.
--> x86: max(swiotlb_size_or_default() + 8MiB, 256MiB)
--> arm64: 128MiB
This one lets the user specify own low range under 4G
for second kernel instead.
0: to disable low allocation.
It will be ignored when crashkernel=X,high is not used
or memory reserved is below 4G.
[KNL, ARM64] range in low memory.
This one lets the user specify a low range in the
DMA zone for the crash dump kernel.
It will be ignored when crashkernel=X,high is not used
or memory reserved is located in the DMA zones.
cryptomgr.notests
[KNL] Disable crypto self-tests

8
arch/arm64/mm/init.c
View File

@ -96,6 +96,8 @@ phys_addr_t __ro_after_init arm64_dma_phys_limit = PHYS_MASK + 1;
#define CRASH_ADDR_LOW_MAX arm64_dma_phys_limit
#define CRASH_ADDR_HIGH_MAX (PHYS_MASK + 1)
#define DEFAULT_CRASH_KERNEL_LOW_SIZE (128UL << 20)
static int __init reserve_crashkernel_low(unsigned long long low_size)
{
unsigned long long low_base;
@ -147,7 +149,9 @@ static void __init reserve_crashkernel(void)
* is not allowed.
*/
ret = parse_crashkernel_low(cmdline, 0, &crash_low_size, &crash_base);
if (ret && (ret != -ENOENT))
if (ret == -ENOENT)
crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
else if (ret)
return;
crash_max = CRASH_ADDR_HIGH_MAX;
@ -170,7 +174,7 @@ static void __init reserve_crashkernel(void)
return;
}
if ((crash_base >= CRASH_ADDR_LOW_MAX) &&
if ((crash_base > CRASH_ADDR_LOW_MAX - crash_low_size) &&
crash_low_size && reserve_crashkernel_low(crash_low_size)) {
memblock_phys_free(crash_base, crash_size);
return;