> On Dec 18, 2019, at 10:21 AM, John Donnelly <john.p.donnelly@xxxxxxxxxx> 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 : > . > [ 0.000000] Movable zone start for each node > [ 0.000000] Early memory node ranges > [ 0.000000] node 0: [mem 0x0000000090000000-0x0000000091ffffff] > [ 0.000000] node 0: [mem 0x0000000092000000-0x00000000928bffff] > [ 0.000000] node 0: [mem 0x00000000928c0000-0x00000000fff9ffff] > [ 0.000000] node 0: [mem 0x00000000fffa0000-0x00000000ffffffff] > [ 0.000000] node 0: [mem 0x0000000880000000-0x0000000fffffffff] > [ 0.000000] node 0: [mem 0x0000008800000000-0x000000bff702ffff]. > > 0x0000008800000000 is the 1st region @35G > > > crashkernel=2048M@35G > > > yields : > > > > [ 0.000000] crashkernel reserved: 0x00000008c0000000- 0x0000000940000000 @ (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&d=DwICAg&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=t2fPg9D87F7D8jm0_3CG9yoiIKdRg4qc_thBw4bzMhc&m=ZAC6UYbT-3qLR3Dvevd09m6neWWzGWSphuvXXlXow68&s=9tn9kUBabiuYhVtXauANSDGaISnCnHLYcAUQgsPBFxs&e= >>> [v1]: https://urldefense.proofpoint.com/v2/url?u=https-3A__lkml.org_lkml_2019_4_2_1174&d=DwICAg&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=t2fPg9D87F7D8jm0_3CG9yoiIKdRg4qc_thBw4bzMhc&m=ZAC6UYbT-3qLR3Dvevd09m6neWWzGWSphuvXXlXow68&s=F-lM7II2cuMF_sK3b6-QhSbWM3X-pI_WZEs0sZitS7A&e= >>> [v2]: https://urldefense.proofpoint.com/v2/url?u=https-3A__lkml.org_lkml_2019_4_9_86&d=DwICAg&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=t2fPg9D87F7D8jm0_3CG9yoiIKdRg4qc_thBw4bzMhc&m=ZAC6UYbT-3qLR3Dvevd09m6neWWzGWSphuvXXlXow68&s=5Y-S6sqMTklHkOQsNtjTX3C7pV05BjKLGhJVfMHEvDs&e= >>> [v3]: https://urldefense.proofpoint.com/v2/url?u=https-3A__lkml.org_lkml_2019_4_9_306&d=DwICAg&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=t2fPg9D87F7D8jm0_3CG9yoiIKdRg4qc_thBw4bzMhc&m=ZAC6UYbT-3qLR3Dvevd09m6neWWzGWSphuvXXlXow68&s=cWn4zSRQupaZ3jjz4eDvD-pNkoLyL_hsZoRx4yJoD0c&e= >>> [v4]: https://urldefense.proofpoint.com/v2/url?u=https-3A__lkml.org_lkml_2019_4_15_273&d=DwICAg&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=t2fPg9D87F7D8jm0_3CG9yoiIKdRg4qc_thBw4bzMhc&m=ZAC6UYbT-3qLR3Dvevd09m6neWWzGWSphuvXXlXow68&s=Nslk4RJKIyIuT0IoQoolXNjupEDXplPhQQwnTSoXNWE&e= >>> [v5]: https://urldefense.proofpoint.com/v2/url?u=https-3A__lkml.org_lkml_2019_5_6_1360&d=DwICAg&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=t2fPg9D87F7D8jm0_3CG9yoiIKdRg4qc_thBw4bzMhc&m=ZAC6UYbT-3qLR3Dvevd09m6neWWzGWSphuvXXlXow68&s=HJVAM6sCxV2DnNg5d4pw8WPqtkmQnKvztEmkSIgtQ5M&e= >>> >>> 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@xxxxxxxxxxxxxxxxxxx >> https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.infradead.org_mailman_listinfo_kexec&d=DwICAg&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=t2fPg9D87F7D8jm0_3CG9yoiIKdRg4qc_thBw4bzMhc&m=ZAC6UYbT-3qLR3Dvevd09m6neWWzGWSphuvXXlXow68&s=XMcFx61B_QPg-FUfG_-t88DKCnGm4grqu6zRguiHYrU&e= > > Hi , Have these changes been promoted to an upstream release ? _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
