e074e3952b
tune sysconfig to save 2nd kernel memory usage The memory in 2nd kernel is limited, we need to use as less memory as we can to ensure vmcore capturing ok. I'm doing below improvements in this patch: 1) numa support is not necessary for kdump kernel, so disable it by adding numa=off to save some kernel mm memory usage. 2) Also add udev.children-max=2 to cmdline to limit max udev chidren processes. 3) For ppc64, ehea driver will by default enable multi queue feature which will use a lot of memory. Almost each ppc machine will oom for network(ssh/nfs) kdump. The module param use_mcs=0 is used to disable multi queue feature. Tested these params on an IBM machine with 2 numa nodes which ooms even for local dump to rootfs. With this patch oom does not happen for local/ssh dump, but for nfs dump oom still happens in the middle of makedumpfile vmcore copying. So there should be other improvement yet. For ehea driver there's other params we can use, but because it's hard to measure the saved memory, I'm waiting for input from IBM people. We can add them later. Signed-off-by: Dave Young <dyoung@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com>
39 lines
1.4 KiB
Plaintext
39 lines
1.4 KiB
Plaintext
# Kernel Version string for the -kdump kernel, such as 2.6.13-1544.FC5kdump
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# If no version is specified, then the init script will try to find a
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# kdump kernel with the same version number as the running kernel.
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KDUMP_KERNELVER=""
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# The kdump commandline is the command line that needs to be passed off to
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# the kdump kernel. This will likely match the contents of the grub kernel
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# line. For example:
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# KDUMP_COMMANDLINE="ro root=LABEL=/"
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# Dracut depends on proper root= options, so please make sure that appropriate
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# root= options are copied from /proc/cmdline. In general it is best to append
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# command line options using "KDUMP_COMMANDLINE_APPEND=".
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# If a command line is not specified, the default will be taken from
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# /proc/cmdline
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KDUMP_COMMANDLINE=""
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# This variable lets us append arguments to the current kdump commandline
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# As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline
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KDUMP_COMMANDLINE_APPEND="maxcpus=1 cgroup_disable=memory numa=off udev.children-max=2"
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# Any additional /sbin/mkdumprd arguments required.
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MKDUMPRD_ARGS=""
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# Any additional kexec arguments required. In most situations, this should
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# be left empty
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#
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# Example:
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# KEXEC_ARGS="--elf32-core-headers"
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KEXEC_ARGS=""
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#Where to find the boot image
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KDUMP_BOOTDIR="/boot"
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#What is the image type used for kdump
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KDUMP_IMG="vmlinuz"
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#What is the images extension. Relocatable kernels don't have one
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KDUMP_IMG_EXT=""
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