| Message ID | 20211123124646.1995-1-thunder.leizhen@huawei.com |
|---|---|
| Headers | show |
| Series | support reserving crashkernel above 4G on arm64 kdump | expand |
For the series:
Tested-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Hi Lei, On 11/23/21 at 08:46pm, Zhen Lei wrote: > There are following issues in arm64 kdump: > 1. We use crashkernel=X to reserve crashkernel below 4G, which > will fail when there is no enough low memory. > 2. If reserving crashkernel above 4G, in this case, crash dump > kernel will boot failure because there is no low memory available > for allocation. > > To solve these issues, change the behavior of crashkernel=X. > crashkernel=X tries low allocation in DMA zone and fall back to high > allocation if it fails. Thanks for this round of posting, I will review the patch series this week. Thanks Baoquan > > We can also use "crashkernel=X,high" to select a high region above > DMA zone, which also tries to allocate at least 256M low memory in > DMA zone automatically and "crashkernel=Y,low" can be used to allocate > specified size low memory. > > When reserving crashkernel in high memory, some low memory is reserved > for crash dump kernel devices. So there may be two regions reserved for > crash dump kernel. > In order to distinct from the high region and make no effect to the use > of existing kexec-tools, rename the low region as "Crash kernel (low)", > and pass the low region by reusing DT property > "linux,usable-memory-range". We made the low memory region as the last > range of "linux,usable-memory-range" to keep compatibility with existing > user-space and older kdump kernels. > > Besides, we need to modify kexec-tools: > arm64: support more than one crash kernel regions(see [1]) > > Another update is document about DT property 'linux,usable-memory-range': > schemas: update 'linux,usable-memory-range' node schema(see [2]) > > This patchset contains the following 11 patches: > > 0001-0004 are some x86 cleanups which prepares for making functionsreserve_crashkernel[_low]() generic. > 0005 makes functions reserve_crashkernel[_low]() generic. > 0006-0008 reimplements arm64 crashkernel=X. > 0009-0010 adds memory for devices by DT property linux,usable-memory-range. > 0011 updates the doc. > > Changes since [v15] > - Aggregate the processing of "linux,usable-memory-range" into one function. > Only patch 9-10 have been updated. > > Changes since [v14] > - Recovering the requirement that the CrashKernel memory regions on X86 > only requires 1 MiB alignment. > - Combine patches 5 and 6 in v14 into one. The compilation warning fixed > by patch 6 was introduced by patch 5 in v14. > - As with crashk_res, crashk_low_res is also processed by > crash_exclude_mem_range() in patch 7. > - Due to commit b261dba2fdb2 ("arm64: kdump: Remove custom linux,usable-memory-range handling") > has removed the architecture-specific code, extend the property "linux,usable-memory-range" > in the platform-agnostic FDT core code. See patch 9. > - Discard the x86 description update in the document, because the description > has been updated by commit b1f4c363666c ("Documentation: kdump: update kdump guide"). > - Change "arm64" to "ARM64" in Doc. > > > Changes since [v13] > - Rebased on top of 5.11-rc5. > - Introduce config CONFIG_ARCH_WANT_RESERVE_CRASH_KERNEL. > Since reserve_crashkernel[_low]() implementations are quite similar on > other architectures, so have CONFIG_ARCH_WANT_RESERVE_CRASH_KERNEL in > arch/Kconfig and select this by X86 and ARM64. > - Some minor cleanup. > > Changes since [v12] > - Rebased on top of 5.10-rc1. > - Keep CRASH_ALIGN as 16M suggested by Dave. > - Drop patch "kdump: add threshold for the required memory". > - Add Tested-by from John. > > Changes since [v11] > - Rebased on top of 5.9-rc4. > - Make the function reserve_crashkernel() of x86 generic. > Suggested by Catalin, make the function reserve_crashkernel() of x86 generic > and arm64 use the generic version to reimplement crashkernel=X. > > Changes since [v10] > - Reimplement crashkernel=X suggested by Catalin, Many thanks to Catalin. > > Changes since [v9] > - Patch 1 add Acked-by from Dave. > - Update patch 5 according to Dave's comments. > - Update chosen schema. > > Changes since [v8] > - Reuse DT property "linux,usable-memory-range". > Suggested by Rob, reuse DT property "linux,usable-memory-range" to pass the low > memory region. > - Fix kdump broken with ZONE_DMA reintroduced. > - Update chosen schema. > > Changes since [v7] > - Move x86 CRASH_ALIGN to 2M > Suggested by Dave and do some test, move x86 CRASH_ALIGN to 2M. > - Update Documentation/devicetree/bindings/chosen.txt. > Add corresponding documentation to Documentation/devicetree/bindings/chosen.txt > suggested by Arnd. > - Add Tested-by from Jhon and pk. > > Changes since [v6] > - Fix build errors reported by kbuild test robot. > > Changes since [v5] > - Move reserve_crashkernel_low() into kernel/crash_core.c. > - Delete crashkernel=X,high. > - Modify crashkernel=X,low. > If crashkernel=X,low is specified simultaneously, reserve spcified size low > memory for crash kdump kernel devices firstly and then reserve memory above 4G. > In addition, rename crashk_low_res as "Crash kernel (low)" for arm64, and then > pass to crash dump kernel by DT property "linux,low-memory-range". > - Update Documentation/admin-guide/kdump/kdump.rst. > > Changes since [v4] > - Reimplement memblock_cap_memory_ranges for multiple ranges by Mike. > > Changes since [v3] > - Add memblock_cap_memory_ranges back for multiple ranges. > - Fix some compiling warnings. > > Changes since [v2] > - Split patch "arm64: kdump: support reserving crashkernel above 4G" as > two. Put "move reserve_crashkernel_low() into kexec_core.c" in a separate > patch. > > Changes since [v1]: > - Move common reserve_crashkernel_low() code into kernel/kexec_core.c. > - Remove memblock_cap_memory_ranges() i added in v1 and implement that > in fdt_enforce_memory_region(). > There are at most two crash kernel regions, for two crash kernel regions > case, we cap the memory range [min(regs[*].start), max(regs[*].end)] > and then remove the memory range in the middle. > > [1]: http://lists.infradead.org/pipermail/kexec/2020-June/020737.html > [2]: https://github.com/robherring/dt-schema/pull/19 > [v1]: https://lkml.org/lkml/2019/4/2/1174 > [v2]: https://lkml.org/lkml/2019/4/9/86 > [v3]: https://lkml.org/lkml/2019/4/9/306 > [v4]: https://lkml.org/lkml/2019/4/15/273 > [v5]: https://lkml.org/lkml/2019/5/6/1360 > [v6]: https://lkml.org/lkml/2019/8/30/142 > [v7]: https://lkml.org/lkml/2019/12/23/411 > [v8]: https://lkml.org/lkml/2020/5/21/213 > [v9]: https://lkml.org/lkml/2020/6/28/73 > [v10]: https://lkml.org/lkml/2020/7/2/1443 > [v11]: https://lkml.org/lkml/2020/8/1/150 > [v12]: https://lkml.org/lkml/2020/9/7/1037 > [v13]: https://lkml.org/lkml/2020/10/31/34 > [v14]: https://lkml.org/lkml/2021/1/30/53 > [v15]: https://lkml.org/lkml/2021/10/19/1405 > > Chen Zhou (10): > x86: kdump: replace the hard-coded alignment with macro CRASH_ALIGN > x86: kdump: make the lower bound of crash kernel reservation > consistent > x86: kdump: use macro CRASH_ADDR_LOW_MAX in functions > reserve_crashkernel() > x86: kdump: move xen_pv_domain() check and insert_resource() to > setup_arch() > x86: kdump: move reserve_crashkernel[_low]() into crash_core.c > arm64: kdump: introduce some macros for crash kernel reservation > arm64: kdump: reimplement crashkernel=X > x86, arm64: Add ARCH_WANT_RESERVE_CRASH_KERNEL config > of: fdt: Add memory for devices by DT property > "linux,usable-memory-range" > kdump: update Documentation about crashkernel > > Zhen Lei (1): > of: fdt: Aggregate the processing of "linux,usable-memory-range" > > Documentation/admin-guide/kdump/kdump.rst | 11 +- > .../admin-guide/kernel-parameters.txt | 11 +- > arch/Kconfig | 3 + > arch/arm64/Kconfig | 1 + > arch/arm64/include/asm/kexec.h | 10 ++ > arch/arm64/kernel/machine_kexec_file.c | 12 +- > arch/arm64/kernel/setup.c | 13 +- > arch/arm64/mm/init.c | 59 ++----- > arch/x86/Kconfig | 2 + > arch/x86/include/asm/elf.h | 3 + > arch/x86/include/asm/kexec.h | 31 +++- > arch/x86/kernel/setup.c | 163 ++---------------- > drivers/of/fdt.c | 45 +++-- > include/linux/crash_core.h | 3 + > include/linux/kexec.h | 2 - > kernel/crash_core.c | 156 +++++++++++++++++ > kernel/kexec_core.c | 17 -- > 17 files changed, 304 insertions(+), 238 deletions(-) > > -- > 2.25.1 >
On 11/23/21 6:46 AM, Zhen Lei wrote: > There are following issues in arm64 kdump: > 1. We use crashkernel=X to reserve crashkernel below 4G, which > will fail when there is no enough low memory. > 2. If reserving crashkernel above 4G, in this case, crash dump > kernel will boot failure because there is no low memory available > for allocation. > > To solve these issues, change the behavior of crashkernel=X. > crashkernel=X tries low allocation in DMA zone and fall back to high > allocation if it fails. > > We can also use "crashkernel=X,high" to select a high region above > DMA zone, which also tries to allocate at least 256M low memory in > DMA zone automatically and "crashkernel=Y,low" can be used to allocate > specified size low memory. > > When reserving crashkernel in high memory, some low memory is reserved > for crash dump kernel devices. So there may be two regions reserved for > crash dump kernel. > In order to distinct from the high region and make no effect to the use > of existing kexec-tools, rename the low region as "Crash kernel (low)", > and pass the low region by reusing DT property > "linux,usable-memory-range". We made the low memory region as the last > range of "linux,usable-memory-range" to keep compatibility with existing > user-space and older kdump kernels. > > Besides, we need to modify kexec-tools: > arm64: support more than one crash kernel regions(see [1]) > > Another update is document about DT property 'linux,usable-memory-range': > schemas: update 'linux,usable-memory-range' node schema(see [2]) > > This patchset contains the following 11 patches: > > 0001-0004 are some x86 cleanups which prepares for making functionsreserve_crashkernel[_low]() generic. > 0005 makes functions reserve_crashkernel[_low]() generic. > 0006-0008 reimplements arm64 crashkernel=X. > 0009-0010 adds memory for devices by DT property linux,usable-memory-range. > 0011 updates the doc. > > Changes since [v15] > - Aggregate the processing of "linux,usable-memory-range" into one function. > Only patch 9-10 have been updated. > > Changes since [v14] > - Recovering the requirement that the CrashKernel memory regions on X86 > only requires 1 MiB alignment. > - Combine patches 5 and 6 in v14 into one. The compilation warning fixed > by patch 6 was introduced by patch 5 in v14. > - As with crashk_res, crashk_low_res is also processed by > crash_exclude_mem_range() in patch 7. > - Due to commit b261dba2fdb2 ("arm64: kdump: Remove custom linux,usable-memory-range handling") > has removed the architecture-specific code, extend the property "linux,usable-memory-range" > in the platform-agnostic FDT core code. See patch 9. > - Discard the x86 description update in the document, because the description > has been updated by commit b1f4c363666c ("Documentation: kdump: update kdump guide"). > - Change "arm64" to "ARM64" in Doc. > > > Changes since [v13] > - Rebased on top of 5.11-rc5. > - Introduce config CONFIG_ARCH_WANT_RESERVE_CRASH_KERNEL. > Since reserve_crashkernel[_low]() implementations are quite similar on > other architectures, so have CONFIG_ARCH_WANT_RESERVE_CRASH_KERNEL in > arch/Kconfig and select this by X86 and ARM64. > - Some minor cleanup. > > Changes since [v12] > - Rebased on top of 5.10-rc1. > - Keep CRASH_ALIGN as 16M suggested by Dave. > - Drop patch "kdump: add threshold for the required memory". > - Add Tested-by from John. > > Changes since [v11] > - Rebased on top of 5.9-rc4. > - Make the function reserve_crashkernel() of x86 generic. > Suggested by Catalin, make the function reserve_crashkernel() of x86 generic > and arm64 use the generic version to reimplement crashkernel=X. > > Changes since [v10] > - Reimplement crashkernel=X suggested by Catalin, Many thanks to Catalin. > > Changes since [v9] > - Patch 1 add Acked-by from Dave. > - Update patch 5 according to Dave's comments. > - Update chosen schema. > > Changes since [v8] > - Reuse DT property "linux,usable-memory-range". > Suggested by Rob, reuse DT property "linux,usable-memory-range" to pass the low > memory region. > - Fix kdump broken with ZONE_DMA reintroduced. > - Update chosen schema. > > Changes since [v7] > - Move x86 CRASH_ALIGN to 2M > Suggested by Dave and do some test, move x86 CRASH_ALIGN to 2M. > - Update Documentation/devicetree/bindings/chosen.txt. > Add corresponding documentation to Documentation/devicetree/bindings/chosen.txt > suggested by Arnd. > - Add Tested-by from Jhon and pk. > > Changes since [v6] > - Fix build errors reported by kbuild test robot. > > Changes since [v5] > - Move reserve_crashkernel_low() into kernel/crash_core.c. > - Delete crashkernel=X,high. > - Modify crashkernel=X,low. > If crashkernel=X,low is specified simultaneously, reserve spcified size low > memory for crash kdump kernel devices firstly and then reserve memory above 4G. > In addition, rename crashk_low_res as "Crash kernel (low)" for arm64, and then > pass to crash dump kernel by DT property "linux,low-memory-range". > - Update Documentation/admin-guide/kdump/kdump.rst. > > Changes since [v4] > - Reimplement memblock_cap_memory_ranges for multiple ranges by Mike. > > Changes since [v3] > - Add memblock_cap_memory_ranges back for multiple ranges. > - Fix some compiling warnings. > > Changes since [v2] > - Split patch "arm64: kdump: support reserving crashkernel above 4G" as > two. Put "move reserve_crashkernel_low() into kexec_core.c" in a separate > patch. > > Changes since [v1]: > - Move common reserve_crashkernel_low() code into kernel/kexec_core.c. > - Remove memblock_cap_memory_ranges() i added in v1 and implement that > in fdt_enforce_memory_region(). > There are at most two crash kernel regions, for two crash kernel regions > case, we cap the memory range [min(regs[*].start), max(regs[*].end)] > and then remove the memory range in the middle. > > [1]: http://lists.infradead.org/pipermail/kexec/2020-June/020737.html > [2]: https://github.com/robherring/dt-schema/pull/19 > [v1]: https://lkml.org/lkml/2019/4/2/1174 > [v2]: https://lkml.org/lkml/2019/4/9/86 > [v3]: https://lkml.org/lkml/2019/4/9/306 > [v4]: https://lkml.org/lkml/2019/4/15/273 > [v5]: https://lkml.org/lkml/2019/5/6/1360 > [v6]: https://lkml.org/lkml/2019/8/30/142 > [v7]: https://lkml.org/lkml/2019/12/23/411 > [v8]: https://lkml.org/lkml/2020/5/21/213 > [v9]: https://lkml.org/lkml/2020/6/28/73 > [v10]: https://lkml.org/lkml/2020/7/2/1443 > [v11]: https://lkml.org/lkml/2020/8/1/150 > [v12]: https://lkml.org/lkml/2020/9/7/1037 > [v13]: https://lkml.org/lkml/2020/10/31/34 > [v14]: https://lkml.org/lkml/2021/1/30/53 > [v15]: https://lkml.org/lkml/2021/10/19/1405 > > Chen Zhou (10): > x86: kdump: replace the hard-coded alignment with macro CRASH_ALIGN > x86: kdump: make the lower bound of crash kernel reservation > consistent > x86: kdump: use macro CRASH_ADDR_LOW_MAX in functions > reserve_crashkernel() > x86: kdump: move xen_pv_domain() check and insert_resource() to > setup_arch() > x86: kdump: move reserve_crashkernel[_low]() into crash_core.c > arm64: kdump: introduce some macros for crash kernel reservation > arm64: kdump: reimplement crashkernel=X > x86, arm64: Add ARCH_WANT_RESERVE_CRASH_KERNEL config > of: fdt: Add memory for devices by DT property > "linux,usable-memory-range" > kdump: update Documentation about crashkernel > > Zhen Lei (1): > of: fdt: Aggregate the processing of "linux,usable-memory-range" > > Documentation/admin-guide/kdump/kdump.rst | 11 +- > .../admin-guide/kernel-parameters.txt | 11 +- > arch/Kconfig | 3 + > arch/arm64/Kconfig | 1 + > arch/arm64/include/asm/kexec.h | 10 ++ > arch/arm64/kernel/machine_kexec_file.c | 12 +- > arch/arm64/kernel/setup.c | 13 +- > arch/arm64/mm/init.c | 59 ++----- > arch/x86/Kconfig | 2 + > arch/x86/include/asm/elf.h | 3 + > arch/x86/include/asm/kexec.h | 31 +++- > arch/x86/kernel/setup.c | 163 ++---------------- > drivers/of/fdt.c | 45 +++-- > include/linux/crash_core.h | 3 + > include/linux/kexec.h | 2 - > kernel/crash_core.c | 156 +++++++++++++++++ > kernel/kexec_core.c | 17 -- > 17 files changed, 304 insertions(+), 238 deletions(-) > Hi, This series has been in review for over 2 years. Can we get this integrated into a build ? Thank you. John.
On Tue, Nov 23, 2021 at 08:46:43PM +0800, Zhen Lei wrote: > diff --git a/arch/Kconfig b/arch/Kconfig > index 26b8ed11639da46..19256aa924c3b2c 100644 > --- a/arch/Kconfig > +++ b/arch/Kconfig > @@ -24,6 +24,9 @@ config KEXEC_ELF > config HAVE_IMA_KEXEC > bool > > +config ARCH_WANT_RESERVE_CRASH_KERNEL > + bool > + > config SET_FS > bool > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index c4207cf9bb17ffb..4b99efa36da3793 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -95,6 +95,7 @@ config ARM64 > select ARCH_WANT_FRAME_POINTERS > select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) > select ARCH_WANT_LD_ORPHAN_WARN > + select ARCH_WANT_RESERVE_CRASH_KERNEL if KEXEC_CORE > select ARCH_WANTS_NO_INSTR > select ARCH_HAS_UBSAN_SANITIZE_ALL > select ARM_AMBA > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 7399327d1eff79d..528034b4276ecf8 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -12,6 +12,7 @@ config X86_32 > depends on !64BIT > # Options that are inherently 32-bit kernel only: > select ARCH_WANT_IPC_PARSE_VERSION > + select ARCH_WANT_RESERVE_CRASH_KERNEL if KEXEC_CORE > select CLKSRC_I8253 > select CLONE_BACKWARDS > select GENERIC_VDSO_32 > @@ -28,6 +29,7 @@ config X86_64 > select ARCH_HAS_GIGANTIC_PAGE > select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 > select ARCH_USE_CMPXCHG_LOCKREF > + select ARCH_WANT_RESERVE_CRASH_KERNEL if KEXEC_CORE > select HAVE_ARCH_SOFT_DIRTY > select MODULES_USE_ELF_RELA > select NEED_DMA_MAP_STATE > diff --git a/kernel/crash_core.c b/kernel/crash_core.c > index 4dc2643fcbccf99..b23cfc0ca8905fd 100644 > --- a/kernel/crash_core.c > +++ b/kernel/crash_core.c > @@ -321,9 +321,7 @@ int __init parse_crashkernel_low(char *cmdline, > * --------- Crashkernel reservation ------------------------------ > */ > > -#ifdef CONFIG_KEXEC_CORE > - > -#if defined(CONFIG_X86) || defined(CONFIG_ARM64) > +#ifdef CONFIG_ARCH_WANT_RESERVE_CRASH_KERNEL > static int __init reserve_crashkernel_low(void) > { > #ifdef CONFIG_64BIT > @@ -451,8 +449,7 @@ void __init reserve_crashkernel(void) > crashk_res.start = crash_base; > crashk_res.end = crash_base + crash_size - 1; > } > -#endif > -#endif /* CONFIG_KEXEC_CORE */ > +#endif /* CONFIG_ARCH_WANT_RESERVE_CRASH_KERNEL */ Nitpick mostly but it may simplify the patches if the x86, arch/Kconfig and crash_core.c changes here could be moved to patch 5. The remaining select for arm64 should be moved to patch 7 and drop the #if change in that patch. This way we can keep the x86 patches on a separate branch. Thanks.
On Tue, Nov 23, 2021 at 08:46:35PM +0800, Zhen Lei wrote: > Chen Zhou (10): > x86: kdump: replace the hard-coded alignment with macro CRASH_ALIGN > x86: kdump: make the lower bound of crash kernel reservation > consistent > x86: kdump: use macro CRASH_ADDR_LOW_MAX in functions > reserve_crashkernel() > x86: kdump: move xen_pv_domain() check and insert_resource() to > setup_arch() > x86: kdump: move reserve_crashkernel[_low]() into crash_core.c > arm64: kdump: introduce some macros for crash kernel reservation > arm64: kdump: reimplement crashkernel=X > x86, arm64: Add ARCH_WANT_RESERVE_CRASH_KERNEL config > of: fdt: Add memory for devices by DT property > "linux,usable-memory-range" > kdump: update Documentation about crashkernel > > Zhen Lei (1): > of: fdt: Aggregate the processing of "linux,usable-memory-range" Apart from a minor comment I made on patch 8 and some comments from Rob that need addressing, the rest looks fine to me. Ingo stated in the past that he's happy to ack the x86 changes as long as there's no functional change (and that's the case AFAICT). Ingo, does your conditional ack still stand? In terms of merging, I'm happy to take it all through the arm64 tree with acks from the x86 maintainers. Alternatively, with the change I mentioned for patch 8, the first 5 patches could be queued via the tip tree on a stable branch and I can base the rest of the arm64 on top. Thomas, Ingo, Peter, any preference? Thanks.
On 2021/12/9 1:09, Catalin Marinas wrote: > On Tue, Nov 23, 2021 at 08:46:43PM +0800, Zhen Lei wrote: >> diff --git a/arch/Kconfig b/arch/Kconfig >> index 26b8ed11639da46..19256aa924c3b2c 100644 >> --- a/arch/Kconfig >> +++ b/arch/Kconfig >> @@ -24,6 +24,9 @@ config KEXEC_ELF >> config HAVE_IMA_KEXEC >> bool >> >> +config ARCH_WANT_RESERVE_CRASH_KERNEL >> + bool >> + >> config SET_FS >> bool >> >> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig >> index c4207cf9bb17ffb..4b99efa36da3793 100644 >> --- a/arch/arm64/Kconfig >> +++ b/arch/arm64/Kconfig >> @@ -95,6 +95,7 @@ config ARM64 >> select ARCH_WANT_FRAME_POINTERS >> select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) >> select ARCH_WANT_LD_ORPHAN_WARN >> + select ARCH_WANT_RESERVE_CRASH_KERNEL if KEXEC_CORE >> select ARCH_WANTS_NO_INSTR >> select ARCH_HAS_UBSAN_SANITIZE_ALL >> select ARM_AMBA >> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig >> index 7399327d1eff79d..528034b4276ecf8 100644 >> --- a/arch/x86/Kconfig >> +++ b/arch/x86/Kconfig >> @@ -12,6 +12,7 @@ config X86_32 >> depends on !64BIT >> # Options that are inherently 32-bit kernel only: >> select ARCH_WANT_IPC_PARSE_VERSION >> + select ARCH_WANT_RESERVE_CRASH_KERNEL if KEXEC_CORE >> select CLKSRC_I8253 >> select CLONE_BACKWARDS >> select GENERIC_VDSO_32 >> @@ -28,6 +29,7 @@ config X86_64 >> select ARCH_HAS_GIGANTIC_PAGE >> select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 >> select ARCH_USE_CMPXCHG_LOCKREF >> + select ARCH_WANT_RESERVE_CRASH_KERNEL if KEXEC_CORE >> select HAVE_ARCH_SOFT_DIRTY >> select MODULES_USE_ELF_RELA >> select NEED_DMA_MAP_STATE >> diff --git a/kernel/crash_core.c b/kernel/crash_core.c >> index 4dc2643fcbccf99..b23cfc0ca8905fd 100644 >> --- a/kernel/crash_core.c >> +++ b/kernel/crash_core.c >> @@ -321,9 +321,7 @@ int __init parse_crashkernel_low(char *cmdline, >> * --------- Crashkernel reservation ------------------------------ >> */ >> >> -#ifdef CONFIG_KEXEC_CORE >> - >> -#if defined(CONFIG_X86) || defined(CONFIG_ARM64) >> +#ifdef CONFIG_ARCH_WANT_RESERVE_CRASH_KERNEL >> static int __init reserve_crashkernel_low(void) >> { >> #ifdef CONFIG_64BIT >> @@ -451,8 +449,7 @@ void __init reserve_crashkernel(void) >> crashk_res.start = crash_base; >> crashk_res.end = crash_base + crash_size - 1; >> } >> -#endif >> -#endif /* CONFIG_KEXEC_CORE */ >> +#endif /* CONFIG_ARCH_WANT_RESERVE_CRASH_KERNEL */ > > Nitpick mostly but it may simplify the patches if the x86, arch/Kconfig > and crash_core.c changes here could be moved to patch 5. The remaining > select for arm64 should be moved to patch 7 and drop the #if change in > that patch. > > This way we can keep the x86 patches on a separate branch. That's a good suggestion. I will do it. > > Thanks. >
On 12/8/21 11:13 AM, Catalin Marinas wrote: > On Tue, Nov 23, 2021 at 08:46:35PM +0800, Zhen Lei wrote: >> Chen Zhou (10): >> x86: kdump: replace the hard-coded alignment with macro CRASH_ALIGN >> x86: kdump: make the lower bound of crash kernel reservation >> consistent >> x86: kdump: use macro CRASH_ADDR_LOW_MAX in functions >> reserve_crashkernel() >> x86: kdump: move xen_pv_domain() check and insert_resource() to >> setup_arch() >> x86: kdump: move reserve_crashkernel[_low]() into crash_core.c >> arm64: kdump: introduce some macros for crash kernel reservation >> arm64: kdump: reimplement crashkernel=X >> x86, arm64: Add ARCH_WANT_RESERVE_CRASH_KERNEL config >> of: fdt: Add memory for devices by DT property >> "linux,usable-memory-range" >> kdump: update Documentation about crashkernel >> >> Zhen Lei (1): >> of: fdt: Aggregate the processing of "linux,usable-memory-range" > > Apart from a minor comment I made on patch 8 and some comments from Rob > that need addressing, the rest looks fine to me. > > Ingo stated in the past that he's happy to ack the x86 changes as long > as there's no functional change (and that's the case AFAICT). Ingo, does > your conditional ack still stand? > > In terms of merging, I'm happy to take it all through the arm64 tree > with acks from the x86 maintainers. Alternatively, with the change I > mentioned for patch 8, the first 5 patches could be queued via the tip > tree on a stable branch and I can base the rest of the arm64 on top. > > Thomas, Ingo, Peter, any preference? > > Thanks. > Hi, If you notice the trend over the past year , some of additional review requests are because the submitter had to rebase to the next version. Can we get this acked and placed in a build so others can test and start using it ? Thank you, JD
On Fri, Dec 10, 2021 at 01:53:59PM -0600, john.p.donnelly@oracle.com wrote: > On 12/8/21 11:13 AM, Catalin Marinas wrote: > > On Tue, Nov 23, 2021 at 08:46:35PM +0800, Zhen Lei wrote: > > > Chen Zhou (10): > > > x86: kdump: replace the hard-coded alignment with macro CRASH_ALIGN > > > x86: kdump: make the lower bound of crash kernel reservation > > > consistent > > > x86: kdump: use macro CRASH_ADDR_LOW_MAX in functions > > > reserve_crashkernel() > > > x86: kdump: move xen_pv_domain() check and insert_resource() to > > > setup_arch() > > > x86: kdump: move reserve_crashkernel[_low]() into crash_core.c > > > arm64: kdump: introduce some macros for crash kernel reservation > > > arm64: kdump: reimplement crashkernel=X > > > x86, arm64: Add ARCH_WANT_RESERVE_CRASH_KERNEL config > > > of: fdt: Add memory for devices by DT property > > > "linux,usable-memory-range" > > > kdump: update Documentation about crashkernel > > > > > > Zhen Lei (1): > > > of: fdt: Aggregate the processing of "linux,usable-memory-range" > > > > Apart from a minor comment I made on patch 8 and some comments from Rob > > that need addressing, the rest looks fine to me. > > > > Ingo stated in the past that he's happy to ack the x86 changes as long > > as there's no functional change (and that's the case AFAICT). Ingo, does > > your conditional ack still stand? > > > > In terms of merging, I'm happy to take it all through the arm64 tree > > with acks from the x86 maintainers. Alternatively, with the change I > > mentioned for patch 8, the first 5 patches could be queued via the tip > > tree on a stable branch and I can base the rest of the arm64 on top. > > > > Thomas, Ingo, Peter, any preference? > > > > Thanks. > > If you notice the trend over the past year , some of additional review > requests are because the submitter had to rebase to the next version. Normally the reviews stand even if the series is rebased. You only drop them if there were non-trivial changes to the patches, not just because of a rebase. Ingo acked the x86 changes in the past but there were some functional changes to the minimum alignment, so the series had to be reworked and the ack not applied. https://lore.kernel.org/r/20200806133627.GB2077191@gmail.com > Can we get this acked and placed in a build so others can test and start > using it ? If Ingo's conditional ack (no functional changes, just a move) still stands over the five x86 patches now, I'm happy to queue them all via the arm64 tree. The latest series here: https://lore.kernel.org/r/20211210065533.2023-1-thunder.leizhen@huawei.com
There are following issues in arm64 kdump: 1. We use crashkernel=X to reserve crashkernel below 4G, which will fail when there is no enough low memory. 2. If reserving crashkernel above 4G, in this case, crash dump kernel will boot failure because there is no low memory available for allocation. To solve these issues, change the behavior of crashkernel=X. crashkernel=X tries low allocation in DMA zone and fall back to high allocation if it fails. We can also use "crashkernel=X,high" to select a high region above DMA zone, which also tries to allocate at least 256M low memory in DMA zone automatically and "crashkernel=Y,low" can be used to allocate specified size low memory. When reserving crashkernel in high memory, some low memory is reserved for crash dump kernel devices. So there may be two regions reserved for crash dump kernel. In order to distinct from the high region and make no effect to the use of existing kexec-tools, rename the low region as "Crash kernel (low)", and pass the low region by reusing DT property "linux,usable-memory-range". We made the low memory region as the last range of "linux,usable-memory-range" to keep compatibility with existing user-space and older kdump kernels. Besides, we need to modify kexec-tools: arm64: support more than one crash kernel regions(see [1]) Another update is document about DT property 'linux,usable-memory-range': schemas: update 'linux,usable-memory-range' node schema(see [2]) This patchset contains the following 11 patches: 0001-0004 are some x86 cleanups which prepares for making functionsreserve_crashkernel[_low]() generic. 0005 makes functions reserve_crashkernel[_low]() generic. 0006-0008 reimplements arm64 crashkernel=X. 0009-0010 adds memory for devices by DT property linux,usable-memory-range. 0011 updates the doc. Changes since [v15] - Aggregate the processing of "linux,usable-memory-range" into one function. Only patch 9-10 have been updated. Changes since [v14] - Recovering the requirement that the CrashKernel memory regions on X86 only requires 1 MiB alignment. - Combine patches 5 and 6 in v14 into one. The compilation warning fixed by patch 6 was introduced by patch 5 in v14. - As with crashk_res, crashk_low_res is also processed by crash_exclude_mem_range() in patch 7. - Due to commit b261dba2fdb2 ("arm64: kdump: Remove custom linux,usable-memory-range handling") has removed the architecture-specific code, extend the property "linux,usable-memory-range" in the platform-agnostic FDT core code. See patch 9. - Discard the x86 description update in the document, because the description has been updated by commit b1f4c363666c ("Documentation: kdump: update kdump guide"). - Change "arm64" to "ARM64" in Doc. Changes since [v13] - Rebased on top of 5.11-rc5. - Introduce config CONFIG_ARCH_WANT_RESERVE_CRASH_KERNEL. Since reserve_crashkernel[_low]() implementations are quite similar on other architectures, so have CONFIG_ARCH_WANT_RESERVE_CRASH_KERNEL in arch/Kconfig and select this by X86 and ARM64. - Some minor cleanup. Changes since [v12] - Rebased on top of 5.10-rc1. - Keep CRASH_ALIGN as 16M suggested by Dave. - Drop patch "kdump: add threshold for the required memory". - Add Tested-by from John. Changes since [v11] - Rebased on top of 5.9-rc4. - Make the function reserve_crashkernel() of x86 generic. Suggested by Catalin, make the function reserve_crashkernel() of x86 generic and arm64 use the generic version to reimplement crashkernel=X. Changes since [v10] - Reimplement crashkernel=X suggested by Catalin, Many thanks to Catalin. Changes since [v9] - Patch 1 add Acked-by from Dave. - Update patch 5 according to Dave's comments. - Update chosen schema. Changes since [v8] - Reuse DT property "linux,usable-memory-range". Suggested by Rob, reuse DT property "linux,usable-memory-range" to pass the low memory region. - Fix kdump broken with ZONE_DMA reintroduced. - Update chosen schema. Changes since [v7] - Move x86 CRASH_ALIGN to 2M Suggested by Dave and do some test, move x86 CRASH_ALIGN to 2M. - Update Documentation/devicetree/bindings/chosen.txt. Add corresponding documentation to Documentation/devicetree/bindings/chosen.txt suggested by Arnd. - Add Tested-by from Jhon and pk. Changes since [v6] - Fix build errors reported by kbuild test robot. Changes since [v5] - Move reserve_crashkernel_low() into kernel/crash_core.c. - Delete crashkernel=X,high. - Modify crashkernel=X,low. If crashkernel=X,low is specified simultaneously, reserve spcified size low memory for crash kdump kernel devices firstly and then reserve memory above 4G. In addition, rename crashk_low_res as "Crash kernel (low)" for arm64, and then pass to crash dump kernel by DT property "linux,low-memory-range". - Update Documentation/admin-guide/kdump/kdump.rst. Changes since [v4] - Reimplement memblock_cap_memory_ranges for multiple ranges by Mike. Changes since [v3] - Add memblock_cap_memory_ranges back for multiple ranges. - Fix some compiling warnings. Changes since [v2] - Split patch "arm64: kdump: support reserving crashkernel above 4G" as two. Put "move reserve_crashkernel_low() into kexec_core.c" in a separate patch. Changes since [v1]: - Move common reserve_crashkernel_low() code into kernel/kexec_core.c. - Remove memblock_cap_memory_ranges() i added in v1 and implement that in fdt_enforce_memory_region(). There are at most two crash kernel regions, for two crash kernel regions case, we cap the memory range [min(regs[*].start), max(regs[*].end)] and then remove the memory range in the middle. [1]: http://lists.infradead.org/pipermail/kexec/2020-June/020737.html [2]: https://github.com/robherring/dt-schema/pull/19 [v1]: https://lkml.org/lkml/2019/4/2/1174 [v2]: https://lkml.org/lkml/2019/4/9/86 [v3]: https://lkml.org/lkml/2019/4/9/306 [v4]: https://lkml.org/lkml/2019/4/15/273 [v5]: https://lkml.org/lkml/2019/5/6/1360 [v6]: https://lkml.org/lkml/2019/8/30/142 [v7]: https://lkml.org/lkml/2019/12/23/411 [v8]: https://lkml.org/lkml/2020/5/21/213 [v9]: https://lkml.org/lkml/2020/6/28/73 [v10]: https://lkml.org/lkml/2020/7/2/1443 [v11]: https://lkml.org/lkml/2020/8/1/150 [v12]: https://lkml.org/lkml/2020/9/7/1037 [v13]: https://lkml.org/lkml/2020/10/31/34 [v14]: https://lkml.org/lkml/2021/1/30/53 [v15]: https://lkml.org/lkml/2021/10/19/1405 Chen Zhou (10): x86: kdump: replace the hard-coded alignment with macro CRASH_ALIGN x86: kdump: make the lower bound of crash kernel reservation consistent x86: kdump: use macro CRASH_ADDR_LOW_MAX in functions reserve_crashkernel() x86: kdump: move xen_pv_domain() check and insert_resource() to setup_arch() x86: kdump: move reserve_crashkernel[_low]() into crash_core.c arm64: kdump: introduce some macros for crash kernel reservation arm64: kdump: reimplement crashkernel=X x86, arm64: Add ARCH_WANT_RESERVE_CRASH_KERNEL config of: fdt: Add memory for devices by DT property "linux,usable-memory-range" kdump: update Documentation about crashkernel Zhen Lei (1): of: fdt: Aggregate the processing of "linux,usable-memory-range" Documentation/admin-guide/kdump/kdump.rst | 11 +- .../admin-guide/kernel-parameters.txt | 11 +- arch/Kconfig | 3 + arch/arm64/Kconfig | 1 + arch/arm64/include/asm/kexec.h | 10 ++ arch/arm64/kernel/machine_kexec_file.c | 12 +- arch/arm64/kernel/setup.c | 13 +- arch/arm64/mm/init.c | 59 ++----- arch/x86/Kconfig | 2 + arch/x86/include/asm/elf.h | 3 + arch/x86/include/asm/kexec.h | 31 +++- arch/x86/kernel/setup.c | 163 ++---------------- drivers/of/fdt.c | 45 +++-- include/linux/crash_core.h | 3 + include/linux/kexec.h | 2 - kernel/crash_core.c | 156 +++++++++++++++++ kernel/kexec_core.c | 17 -- 17 files changed, 304 insertions(+), 238 deletions(-)