Re: [PATCH v6 0/4] support reserving crashkernel above 4G on arm64 kdump
Hi, <. — Snip. —>. Have these changes been promoted in any upstream releases ? Thanks, John. ___ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
Re: [PATCH v6 0/4] support reserving crashkernel above 4G on arm64 kdump
> On Dec 18, 2019, at 10:21 AM, John Donnelly > wrote: > > On 12/17/19 8:07 PM, Chen Zhou wrote: > > Hi > See inline below > >> Hi all, >> Friendly ping... >> On 2019/8/30 15:11, Chen Zhou wrote: >>> I am busy with other things, so it was a long time before this version was >>> released. >>> >>> This patch series enable reserving crashkernel above 4G in arm64. >>> >>> 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. Currently, crashkernel=Y@X can be used to reserve crashkernel above 4G, >>> in this case, if swiotlb or DMA buffers are requierd, crash dump kernel >>> will boot failure because there is no low memory available for allocation. >>> >>> To solve these issues, introduce crashkernel=X,low to reserve specified >>> size low memory. >>> Crashkernel=X tries to reserve memory for the crash dump kernel under >>> 4G. If crashkernel=Y,low is specified simultaneously, reserve spcified >>> size low memory for crash kdump kernel devices firstly and then reserve >>> memory above 4G. >>> >>> When crashkernel is reserved above 4G in memory, that is, crashkernel=X,low >>> is specified simultaneously, kernel should reserve specified size low memory >>> for crash dump kernel devices. So there may be two crash kernel regions, one >>> is below 4G, the other is above 4G. >>> In order to distinct from the high region and make no effect to the use of >>> kexec-tools, rename the low region as "Crash kernel (low)", and add DT >>> property >>> "linux,low-memory-range" to crash dump kernel's dtb to pass the low region. > > > > > Hi , > > I have found that 5.4 Arm kernels can safely use 768M crashkernel size for " > standard" crash dumps that write a minimal vmcore to local storage. While > "standard" may vary, I say that is default out of box delivery. > > If you a introduce more elaborate setup that use networking and NFS, a larger > crashkernel is needed, and since 1024MB size is not available, I found using > the 1st available range above 4GB on node-0 works: > > > > Set the crash dump to be in the 1st 35G region on node-0 after 4G : > . > [0.00] Movable zone start for each node > [0.00] Early memory node ranges > [0.00] node 0: [mem 0x9000-0x91ff] > [0.00] node 0: [mem 0x9200-0x928b] > [0.00] node 0: [mem 0x928c-0xfff9] > [0.00] node 0: [mem 0xfffa-0x] > [0.00] node 0: [mem 0x00088000-0x000f] > [0.00] node 0: [mem 0x0088-0x00bff702]. > > 0x0088 is the 1st region @35G > > > crashkernel=2048M@35G > > > yields : > > > > [0.00] crashkernel reserved: 0x0008c000- 0x00094000 > @ (2048 MB) > > Now we have very large Arm server class systems with GB of memory so 2GB > crashkernel is not much of an impact > > No modifications are needed. > > I submitted a RFC awhile back to add crashkernel=auto upstream that hasn't > been reviewed yet that could be used to set various Arm crash sizes like x86 > does. > > > >>> >>> Besides, we need to modify kexec-tools: >>> arm64: kdump: add another DT property to crash dump kernel's dtb(see [1]) >>> >>> The previous changes and discussions can be retrieved from: >>> >>> 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]: >>>
Re: [PATCH v6 0/4] support reserving crashkernel above 4G on arm64 kdump
Hi John, On 2019/12/19 1:18, John Donnelly wrote: > HI > > SEE INLINE ON A QUESTION : > >> On Dec 17, 2019, at 8:07 PM, Chen Zhou wrote: >> >> Hi all, >> >> Friendly ping... >> >> On 2019/8/30 15:11, Chen Zhou wrote: >>> I am busy with other things, so it was a long time before this version was >>> released. >>> >>> This patch series enable reserving crashkernel above 4G in arm64. >>> >>> 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. Currently, crashkernel=Y@X can be used to reserve crashkernel above 4G, >>> in this case, if swiotlb or DMA buffers are requierd, crash dump kernel >>> will boot failure because there is no low memory available for allocation. > > > Can you elaborate when the boot failures may fail due to lacking > swiotlb or DMA buffers ? Are these related to certain adapters or specific > platforms ? > > I have not seen this when using crashkernel=2024M@35GB . > For example, in my environment "Huawei TaiShan 2280", we need to use mpt3sas driver in crash dump kernel for dumping vmcore. mpt3sas driver needs to call dma_pool_alloc to allocate some pages, if there is no DMA buffer, page allocation will fail, which leads to crash dump kernel boot failure, like this: [2019/12/19 9:12:41] [ 12.403501] mpt3sas_cm0: diag reset: SUCCESS [2019/12/19 9:12:41] [ 12.456076] mpt3sas_cm0: reply_post_free pool: dma_pool_alloc failed [2019/12/19 9:12:41] [ 12.462515] pci 0004:48:00.0: can't derive routing for PCI INT A [2019/12/19 9:12:41] [ 12.468761] mpt3sas 0004:49:00.0: PCI INT A: no GSI [2019/12/19 9:12:41] [ 12.476348] mpt3sas_cm0: failure at drivers/scsi/mpt3sas/mpt3sas_scsih.c:10626/_scsih_probe()! [2019/12/19 9:14:38] [ TIME ] Timed out waiting for device dev-di…b3\x2d890a\x2d2ead7df26f48.device. [2019/12/19 9:14:38] [DEPEND] Dependency failed for Initrd Root Device. [2019/12/19 9:14:38] [DEPEND] Dependency failed for /sysroot. [2019/12/19 9:14:38] [DEPEND] Dependency failed for Initrd Root File System. [2019/12/19 9:14:38] [DEPEND] Dependency failed for Reload Configuration from the Real Root. [2019/12/19 9:14:38] [DEPEND] Dependency failed for File System C…40bae-9eb8-46b3-890a-2ead7df26f48. Thanks, Chen Zhou > >>> >>> To solve these issues, introduce crashkernel=X,low to reserve specified >>> size low memory. >>> Crashkernel=X tries to reserve memory for the crash dump kernel under >>> 4G. If crashkernel=Y,low is specified simultaneously, reserve spcified >>> size low memory for crash kdump kernel devices firstly and then reserve >>> memory above 4G. >>> >>> When crashkernel is reserved above 4G in memory, that is, crashkernel=X,low >>> is specified simultaneously, kernel should reserve specified size low memory >>> for crash dump kernel devices. So there may be two crash kernel regions, one >>> is below 4G, the other is above 4G. >>> In order to distinct from the high region and make no effect to the use of >>> kexec-tools, rename the low region as "Crash kernel (low)", and add DT >>> property >>> "linux,low-memory-range" to crash dump kernel's dtb to pass the low region. >>> >>> Besides, we need to modify kexec-tools: >>> arm64: kdump: add another DT property to crash dump kernel's dtb(see [1]) >>> >>> The previous changes and discussions can be retrieved from: >>> >>> 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]: >>>
Re: [PATCH v6 0/4] support reserving crashkernel above 4G on arm64 kdump
Hi Will On 2019/12/18 17:09, Will Deacon wrote: > On Wed, Dec 18, 2019 at 10:07:59AM +0800, Chen Zhou wrote: >> Friendly ping... > > You broke the build: > > https://lore.kernel.org/lkml/201909010744.cde940pv%...@intel.com > https://lore.kernel.org/lkml/201909010704.4m9y2sg7%...@intel.com > > So I doubt anybody will seriously look at this. I was also waiting for other suggestions. I will fix this in next version. > > Will > > . Thanks, Chen Zhou ___ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
Re: [PATCH v6 0/4] support reserving crashkernel above 4G on arm64 kdump
HI SEE INLINE ON A QUESTION : > On Dec 17, 2019, at 8:07 PM, Chen Zhou wrote: > > Hi all, > > Friendly ping... > > On 2019/8/30 15:11, Chen Zhou wrote: >> I am busy with other things, so it was a long time before this version was >> released. >> >> This patch series enable reserving crashkernel above 4G in arm64. >> >> 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. Currently, crashkernel=Y@X can be used to reserve crashkernel above 4G, >> in this case, if swiotlb or DMA buffers are requierd, crash dump kernel >> will boot failure because there is no low memory available for allocation. Can you elaborate when the boot failures may fail due to lacking swiotlb or DMA buffers ? Are these related to certain adapters or specific platforms ? I have not seen this when using crashkernel=2024M@35GB . >> >> To solve these issues, introduce crashkernel=X,low to reserve specified >> size low memory. >> Crashkernel=X tries to reserve memory for the crash dump kernel under >> 4G. If crashkernel=Y,low is specified simultaneously, reserve spcified >> size low memory for crash kdump kernel devices firstly and then reserve >> memory above 4G. >> >> When crashkernel is reserved above 4G in memory, that is, crashkernel=X,low >> is specified simultaneously, kernel should reserve specified size low memory >> for crash dump kernel devices. So there may be two crash kernel regions, one >> is below 4G, the other is above 4G. >> In order to distinct from the high region and make no effect to the use of >> kexec-tools, rename the low region as "Crash kernel (low)", and add DT >> property >> "linux,low-memory-range" to crash dump kernel's dtb to pass the low region. >> >> Besides, we need to modify kexec-tools: >> arm64: kdump: add another DT property to crash dump kernel's dtb(see [1]) >> >> The previous changes and discussions can be retrieved from: >> >> 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]: >> https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.infradead.org_pipermail_kexec_2019-2DAugust_023569.html=DwICAg=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE=t2fPg9D87F7D8jm0_3CG9yoiIKdRg4qc_thBw4bzMhc=ZAC6UYbT-3qLR3Dvevd09m6neWWzGWSphuvXXlXow68=9tn9kUBabiuYhVtXauANSDGaISnCnHLYcAUQgsPBFxs= >> >> [v1]: >> https://urldefense.proofpoint.com/v2/url?u=https-3A__lkml.org_lkml_2019_4_2_1174=DwICAg=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE=t2fPg9D87F7D8jm0_3CG9yoiIKdRg4qc_thBw4bzMhc=ZAC6UYbT-3qLR3Dvevd09m6neWWzGWSphuvXXlXow68=F-lM7II2cuMF_sK3b6-QhSbWM3X-pI_WZEs0sZitS7A= >> >> [v2]: >> https://urldefense.proofpoint.com/v2/url?u=https-3A__lkml.org_lkml_2019_4_9_86=DwICAg=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE=t2fPg9D87F7D8jm0_3CG9yoiIKdRg4qc_thBw4bzMhc=ZAC6UYbT-3qLR3Dvevd09m6neWWzGWSphuvXXlXow68=5Y-S6sqMTklHkOQsNtjTX3C7pV05BjKLGhJVfMHEvDs= >> >> [v3]: >> https://urldefense.proofpoint.com/v2/url?u=https-3A__lkml.org_lkml_2019_4_9_306=DwICAg=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE=t2fPg9D87F7D8jm0_3CG9yoiIKdRg4qc_thBw4bzMhc=ZAC6UYbT-3qLR3Dvevd09m6neWWzGWSphuvXXlXow68=cWn4zSRQupaZ3jjz4eDvD-pNkoLyL_hsZoRx4yJoD0c= >> >> [v4]: >> https://urldefense.proofpoint.com/v2/url?u=https-3A__lkml.org_lkml_2019_4_15_273=DwICAg=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE=t2fPg9D87F7D8jm0_3CG9yoiIKdRg4qc_thBw4bzMhc=ZAC6UYbT-3qLR3Dvevd09m6neWWzGWSphuvXXlXow68=Nslk4RJKIyIuT0IoQoolXNjupEDXplPhQQwnTSoXNWE= >> >> [v5]: >>
Re: [PATCH v6 0/4] support reserving crashkernel above 4G on arm64 kdump
On 12/17/19 8:07 PM, Chen Zhou wrote: Hi See inline below Hi all, Friendly ping... On 2019/8/30 15:11, Chen Zhou wrote: I am busy with other things, so it was a long time before this version was released. This patch series enable reserving crashkernel above 4G in arm64. 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. Currently, crashkernel=Y@X can be used to reserve crashkernel above 4G, in this case, if swiotlb or DMA buffers are requierd, crash dump kernel will boot failure because there is no low memory available for allocation. To solve these issues, introduce crashkernel=X,low to reserve specified size low memory. Crashkernel=X tries to reserve memory for the crash dump kernel under 4G. If crashkernel=Y,low is specified simultaneously, reserve spcified size low memory for crash kdump kernel devices firstly and then reserve memory above 4G. When crashkernel is reserved above 4G in memory, that is, crashkernel=X,low is specified simultaneously, kernel should reserve specified size low memory for crash dump kernel devices. So there may be two crash kernel regions, one is below 4G, the other is above 4G. In order to distinct from the high region and make no effect to the use of kexec-tools, rename the low region as "Crash kernel (low)", and add DT property "linux,low-memory-range" to crash dump kernel's dtb to pass the low region. Hi , I have found that 5.4 Arm kernels can safely use 768M crashkernel size for " standard" crash dumps that write a minimal vmcore to local storage. While "standard" may vary, I say that is default out of box delivery. If you a introduce more elaborate setup that use networking and NFS, a larger crashkernel is needed, and since 1024MB size is not available, I found using the 1st available range above 4GB on node-0 works: Set the crash dump to be in the 1st 35G region on node-0 after 4G : . [0.00] Movable zone start for each node [0.00] Early memory node ranges [0.00] node 0: [mem 0x9000-0x91ff] [0.00] node 0: [mem 0x9200-0x928b] [0.00] node 0: [mem 0x928c-0xfff9] [0.00] node 0: [mem 0xfffa-0x] [0.00] node 0: [mem 0x00088000-0x000f] [0.00] node 0: [mem 0x0088-0x00bff702]. 0x0088 is the 1st region @35G crashkernel=2048M@35G yields : [0.00] crashkernel reserved: 0x0008c000- 0x00094000 @ (2048 MB) Now we have very large Arm server class systems with GB of memory so 2GB crashkernel is not much of an impact No modifications are needed. I submitted a RFC awhile back to add crashkernel=auto upstream that hasn't been reviewed yet that could be used to set various Arm crash sizes like x86 does. Besides, we need to modify kexec-tools: arm64: kdump: add another DT property to crash dump kernel's dtb(see [1]) The previous changes and discussions can be retrieved from: 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]: https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.infradead.org_pipermail_kexec_2019-2DAugust_023569.html=DwICAg=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE=t2fPg9D87F7D8jm0_3CG9yoiIKdRg4qc_thBw4bzMhc=ZAC6UYbT-3qLR3Dvevd09m6neWWzGWSphuvXXlXow68=9tn9kUBabiuYhVtXauANSDGaISnCnHLYcAUQgsPBFxs= [v1]:
Re: [PATCH v6 0/4] support reserving crashkernel above 4G on arm64 kdump
On Wed, Dec 18, 2019 at 10:07:59AM +0800, Chen Zhou wrote: > Friendly ping... You broke the build: https://lore.kernel.org/lkml/201909010744.cde940pv%...@intel.com https://lore.kernel.org/lkml/201909010704.4m9y2sg7%...@intel.com So I doubt anybody will seriously look at this. Will ___ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
Re: [PATCH v6 0/4] support reserving crashkernel above 4G on arm64 kdump
Hi all, Friendly ping... On 2019/8/30 15:11, Chen Zhou wrote: > I am busy with other things, so it was a long time before this version was > released. > > This patch series enable reserving crashkernel above 4G in arm64. > > 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. Currently, crashkernel=Y@X can be used to reserve crashkernel above 4G, > in this case, if swiotlb or DMA buffers are requierd, crash dump kernel > will boot failure because there is no low memory available for allocation. > > To solve these issues, introduce crashkernel=X,low to reserve specified > size low memory. > Crashkernel=X tries to reserve memory for the crash dump kernel under > 4G. If crashkernel=Y,low is specified simultaneously, reserve spcified > size low memory for crash kdump kernel devices firstly and then reserve > memory above 4G. > > When crashkernel is reserved above 4G in memory, that is, crashkernel=X,low > is specified simultaneously, kernel should reserve specified size low memory > for crash dump kernel devices. So there may be two crash kernel regions, one > is below 4G, the other is above 4G. > In order to distinct from the high region and make no effect to the use of > kexec-tools, rename the low region as "Crash kernel (low)", and add DT > property > "linux,low-memory-range" to crash dump kernel's dtb to pass the low region. > > Besides, we need to modify kexec-tools: > arm64: kdump: add another DT property to crash dump kernel's dtb(see [1]) > > The previous changes and discussions can be retrieved from: > > 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/2019-August/023569.html > [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 > > Chen Zhou (4): > x86: kdump: move reserve_crashkernel_low() into crash_core.c > arm64: kdump: reserve crashkenel above 4G for crash dump kernel > arm64: kdump: add memory for devices by DT property, low-memory-range > kdump: update Documentation about crashkernel on arm64 > > Documentation/admin-guide/kdump/kdump.rst | 13 - > Documentation/admin-guide/kernel-parameters.txt | 12 - > arch/arm64/include/asm/kexec.h | 3 ++ > arch/arm64/kernel/setup.c | 8 ++- > arch/arm64/mm/init.c| 61 +-- > arch/x86/include/asm/kexec.h| 3 ++ > arch/x86/kernel/setup.c | 65 > +++-- > include/linux/crash_core.h | 4 ++ > include/linux/kexec.h | 1 - > kernel/crash_core.c | 65 > + > 10 files changed, 168 insertions(+), 67 deletions(-) > ___ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
[PATCH v6 0/4] support reserving crashkernel above 4G on arm64 kdump
I am busy with other things, so it was a long time before this version was released. This patch series enable reserving crashkernel above 4G in arm64. 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. Currently, crashkernel=Y@X can be used to reserve crashkernel above 4G, in this case, if swiotlb or DMA buffers are requierd, crash dump kernel will boot failure because there is no low memory available for allocation. To solve these issues, introduce crashkernel=X,low to reserve specified size low memory. Crashkernel=X tries to reserve memory for the crash dump kernel under 4G. If crashkernel=Y,low is specified simultaneously, reserve spcified size low memory for crash kdump kernel devices firstly and then reserve memory above 4G. When crashkernel is reserved above 4G in memory, that is, crashkernel=X,low is specified simultaneously, kernel should reserve specified size low memory for crash dump kernel devices. So there may be two crash kernel regions, one is below 4G, the other is above 4G. In order to distinct from the high region and make no effect to the use of kexec-tools, rename the low region as "Crash kernel (low)", and add DT property "linux,low-memory-range" to crash dump kernel's dtb to pass the low region. Besides, we need to modify kexec-tools: arm64: kdump: add another DT property to crash dump kernel's dtb(see [1]) The previous changes and discussions can be retrieved from: 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/2019-August/023569.html [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 Chen Zhou (4): x86: kdump: move reserve_crashkernel_low() into crash_core.c arm64: kdump: reserve crashkenel above 4G for crash dump kernel arm64: kdump: add memory for devices by DT property, low-memory-range kdump: update Documentation about crashkernel on arm64 Documentation/admin-guide/kdump/kdump.rst | 13 - Documentation/admin-guide/kernel-parameters.txt | 12 - arch/arm64/include/asm/kexec.h | 3 ++ arch/arm64/kernel/setup.c | 8 ++- arch/arm64/mm/init.c| 61 +-- arch/x86/include/asm/kexec.h| 3 ++ arch/x86/kernel/setup.c | 65 +++-- include/linux/crash_core.h | 4 ++ include/linux/kexec.h | 1 - kernel/crash_core.c | 65 + 10 files changed, 168 insertions(+), 67 deletions(-) -- 2.7.4
