2040103bd7
Check the number of cpus for x86_64 kdump kernel to boot with. We met an issue on x86_64: kdump runs out of vectors with the default "nr_cpus=1", when requesting tons of irqs. This patch detects such situation and warns users about the risk. The total number of vectors percpu is 256 defined by x86 architecture. The available vectors can be allocated to io devices percpu starts from FIRST_EXTERNAL_VECTOR(see kernel code), and some high-numbered ones are consumed by some system interrupts. As a result, the vectors for io device are within [FIRST_EXTERNAL_VECTOR, FIRST_SYSTEM_VECTOR), with one known exception, 0x80 within the range is reserved specially as the syscall vector. FIRST_EXTERNAL_VECTOR is invariably 32, while FIRST_SYSTEM_VECTOR can vary between different kernel versions. E.g. FIRST_SYSTEM_VECTOR gets 0xef(with CONFIG_X86_LOCAL_APIC on)for linux-4.10, that is 17 vectors reserved, considering it may increase in the future and the special vectors, we use a flexible variance and assume there are 32 reserved from FIRST_EXTERNAL_VECTOR. Then the max vectors for device interrupts percpu is: (256-32)-32=192, we acquire the number N of device interrupts from /proc/irq/, then the number of minimal cpus required is calculated: (N + 192 - 1) / 192 Signed-off-by: Xunlei Pang <xlpang@redhat.com> Acked-by: Pratyush Anand <panand@redhat.com> Acked-by: Dave Young <dyoung@redhat.com> |
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|---|---|---|
| anaconda-addon | ||
| .gitignore | ||
| 98-kexec.rules | ||
| README | ||
| dracut-kdump-capture.service | ||
| dracut-kdump-emergency.service | ||
| dracut-kdump-error-handler.service | ||
| dracut-kdump-error-handler.sh | ||
| dracut-kdump.sh | ||
| dracut-module-setup.sh | ||
| dracut-monitor_dd_progress | ||
| fadump-howto.txt | ||
| kdump-dep-generator.sh | ||
| kdump-in-cluster-environment.txt | ||
| kdump-lib-initramfs.sh | ||
| kdump-lib.sh | ||
| kdump.conf | ||
| kdump.conf.5 | ||
| kdump.service | ||
| kdump.sysconfig | ||
| kdump.sysconfig.i386 | ||
| kdump.sysconfig.ppc64 | ||
| kdump.sysconfig.ppc64le | ||
| kdump.sysconfig.s390x | ||
| kdump.sysconfig.x86_64 | ||
| kdumpctl | ||
| kdumpctl.8 | ||
| kexec-kdump-howto.txt | ||
| kexec-tools-2.0.3-disable-kexec-test.patch | ||
| kexec-tools.spec | ||
| live-image-kdump-howto.txt | ||
| mkdumprd | ||
| mkdumprd.8 | ||
| rhcrashkernel-param | ||
| sources | ||
| zanata-notes.txt | ||
README
Adding a patch to kexec-tools ============================= There is a mailing list kexec@lists.fedoraproject.org where all the dicussion related to fedora kexec-tools happen. All the patches are posted there for inclusion and committed to kexec-tools after review. So if you want your patches to be included in fedora kexec-tools package, post these to kexec@lists.fedoraproject.org. One can subscribe to list and browse through archives here. https://admin.fedoraproject.org/mailman/listinfo/kexec