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tune sysconfig to save memory usage

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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>
This commit is contained in:
dyoung@redhat.com 2013-02-26 16:09:11 +08:00 committed by Baoquan He
parent 71d27e8b17
commit e074e3952b
4 changed files with 4 additions and 4 deletions
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2
kdump.sysconfig.i386
View File

@ -16,7 +16,7 @@ KDUMP_COMMANDLINE=""
# This variable lets us append arguments to the current kdump commandline
# As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline
KDUMP_COMMANDLINE_APPEND="irqpoll nr_cpus=1 reset_devices"
KDUMP_COMMANDLINE_APPEND="irqpoll nr_cpus=1 reset_devices numa=off udev.children-max=2"
# Any additional kexec arguments required. In most situations, this should
# be left empty

2
kdump.sysconfig.ppc64
View File

@ -16,7 +16,7 @@ KDUMP_COMMANDLINE=""
# This variable lets us append arguments to the current kdump commandline
# As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline
KDUMP_COMMANDLINE_APPEND="irqpoll maxcpus=1 noirqdistrib reset_devices cgroup_disable=memory"
KDUMP_COMMANDLINE_APPEND="irqpoll maxcpus=1 noirqdistrib reset_devices cgroup_disable=memory numa=off udev.children-max=2 ehea.use_mcs=0"
# Any additional kexec arguments required. In most situations, this should
# be left empty

2
kdump.sysconfig.s390x
View File

@ -16,7 +16,7 @@ KDUMP_COMMANDLINE=""
# This variable lets us append arguments to the current kdump commandline
# As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline
KDUMP_COMMANDLINE_APPEND="maxcpus=1 cgroup_disable=memory"
KDUMP_COMMANDLINE_APPEND="maxcpus=1 cgroup_disable=memory numa=off udev.children-max=2"
# Any additional /sbin/mkdumprd arguments required.
MKDUMPRD_ARGS=""

2
kdump.sysconfig.x86_64
View File

@ -16,7 +16,7 @@ KDUMP_COMMANDLINE=""
# This variable lets us append arguments to the current kdump commandline
# As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline
KDUMP_COMMANDLINE_APPEND="irqpoll nr_cpus=1 reset_devices cgroup_disable=memory mce=off"
KDUMP_COMMANDLINE_APPEND="irqpoll nr_cpus=1 reset_devices cgroup_disable=memory mce=off numa=off udev.children-max=2"
# Any additional kexec arguments required. In most situations, this should
# be left empty