| Message ID | 20220609135029.607-1-thunder.leizhen@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: kdump: Provide default size when crashkernel=Y,low is not specified | expand |
Please ignore this patch, I have post an new patch set. Put: default low size, fall back and optimization together. On 2022/6/9 21:50, Zhen Lei wrote: > To be consistent with the implementation of x86 and improve cross-platform > user experience. Try to allocate at least 256 MiB low memory automatically > when crashkernel=Y,low is not specified. > > Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> > --- > Documentation/admin-guide/kernel-parameters.txt | 10 +++------- > arch/arm64/mm/init.c | 12 +++++++++++- > 2 files changed, 14 insertions(+), 8 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 8090130b544b070..9560f5af248e0d6 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -843,7 +843,9 @@ > 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(For some platforms, > + not all low 4G memory can be directly accessed by devices, > + use the DMA zones instead). 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 > @@ -857,12 +859,6 @@ > 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 > > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > index 339ee84e5a61a0b..5390f361208ccf7 100644 > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -96,6 +96,14 @@ 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) > > +/* > + * This is an empirical value in x86_64 and taken here directly. Please > + * refer to the code comment in reserve_crashkernel_low() of x86_64 for more > + * details. > + */ > +#define DEFAULT_CRASH_KERNEL_LOW_SIZE \ > + max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20) > + > static int __init reserve_crashkernel_low(unsigned long long low_size) > { > unsigned long long low_base; > @@ -147,7 +155,9 @@ 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; >
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 8090130b544b070..9560f5af248e0d6 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -843,7 +843,9 @@ 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(For some platforms, + not all low 4G memory can be directly accessed by devices, + use the DMA zones instead). 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 @@ -857,12 +859,6 @@ 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 diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 339ee84e5a61a0b..5390f361208ccf7 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -96,6 +96,14 @@ 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) +/* + * This is an empirical value in x86_64 and taken here directly. Please + * refer to the code comment in reserve_crashkernel_low() of x86_64 for more + * details. + */ +#define DEFAULT_CRASH_KERNEL_LOW_SIZE \ + max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20) + static int __init reserve_crashkernel_low(unsigned long long low_size) { unsigned long long low_base; @@ -147,7 +155,9 @@ 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;
To be consistent with the implementation of x86 and improve cross-platform user experience. Try to allocate at least 256 MiB low memory automatically when crashkernel=Y,low is not specified. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> --- Documentation/admin-guide/kernel-parameters.txt | 10 +++------- arch/arm64/mm/init.c | 12 +++++++++++- 2 files changed, 14 insertions(+), 8 deletions(-)