| Message ID | 20220613080932.663-2-thunder.leizhen@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: kdump: Function supplement and performance optimization | expand |
On 06/13/22 at 04:09pm, 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. This should correspond to the case that crashkernel=,high is explicitly specified, while crashkenrel=,low is omitted. It could be better to mention these. Otherwise, this looks good to me. > > Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> > --- > Documentation/admin-guide/kernel-parameters.txt | 8 +------- > arch/arm64/mm/init.c | 12 +++++++++++- > 2 files changed, 12 insertions(+), 8 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 8090130b544b070..61b179232b68001 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -843,7 +843,7 @@ > 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 ~~~~ exceeds 80 characters, it should be OK. > 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 +857,6 @@ > 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; > -- > 2.25.1 >
On 2022/6/17 10:40, Baoquan He wrote: > On 06/13/22 at 04:09pm, 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. > > This should correspond to the case that crashkernel=,high is explicitly > specified, while crashkenrel=,low is omitted. It could be better to > mention these. Okay, I'll update the description in the next version. > > Otherwise, this looks good to me. > >> >> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> >> --- >> Documentation/admin-guide/kernel-parameters.txt | 8 +------- >> arch/arm64/mm/init.c | 12 +++++++++++- >> 2 files changed, 12 insertions(+), 8 deletions(-) >> >> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt >> index 8090130b544b070..61b179232b68001 100644 >> --- a/Documentation/admin-guide/kernel-parameters.txt >> +++ b/Documentation/admin-guide/kernel-parameters.txt >> @@ -843,7 +843,7 @@ >> 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 > ~~~~ exceeds 80 characters, it should be OK. > >> 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 +857,6 @@ >> 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; >> -- >> 2.25.1 >> > > . >
On 06/13/22 at 04:09pm, 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 | 8 +------- > arch/arm64/mm/init.c | 12 +++++++++++- > 2 files changed, 12 insertions(+), 8 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 8090130b544b070..61b179232b68001 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -843,7 +843,7 @@ > 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 > @@ -857,12 +857,6 @@ > 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) About this default low value, 256M, I am not sure if it can be lowered down. We have Ampere Mt-Jade systems in Redhat and their biggest contiguous memory is less than 256M under low 4G when the firmware 32bit option is disabled. Obviously this will fail the default crashkernel,low value. I am not sure how common the 32bit option is disabled. If it's an important feature and widely set, it need be taken into consideration when deciding this default crashkernel,low value. Otherwise, the crashkernel=xM won't work in Ampere Mt-Jade system with 32bit option disabled, and people need specify crashkernel=xM,high, crashkernel=yM,low explicitly. The omission of crashkernel,low is also not allowed in the case. Hi, Mark and Christopher, Add you in CC. If you happen to know contact person from Ampere, please also feel free to add them in this thread. Thanks Baoquan > 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; > -- > 2.25.1 >
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 8090130b544b070..61b179232b68001 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -843,7 +843,7 @@ 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 @@ -857,12 +857,6 @@ 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 | 8 +------- arch/arm64/mm/init.c | 12 +++++++++++- 2 files changed, 12 insertions(+), 8 deletions(-)