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Commit ebf137f6 authored by Zhou Wenjian's avatar Zhou Wenjian Committed by Jonathan Corbet
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Documentation: kdump: Add description of enable multi-cpus support 



Multi-cpu support is useful to improve the performance of kdump in
some cases. So add the description of enable multi-cpu support in
dump-capture kernel.

Signed-off-by: default avatarZhou Wenjian <zhouwj-fnst@cn.fujitsu.com>
Acked-by: default avatarBaoquan He <bhe@redhat.com>
Acked-by: default avatarXunlei Pang <xpang@redhat.com>
Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
parent 3dfb4c1b

Documentation/kdump/kdump.txt

+7 −0
Original line number Diff line number Diff line
@@ -396,6 +396,13 @@ Notes on loading the dump-capture kernel: 
  Note, though maxcpus always works, you had better replace it with

  nr_cpus to save memory if supported by the current ARCH, such as x86.



* You should enable multi-cpu support in dump-capture kernel if you intend

  to use multi-thread programs with it, such as parallel dump feature of

  makedumpfile. Otherwise, the multi-thread program may have a great

  performance degradation. To enable multi-cpu support, you should bring up an

  SMP dump-capture kernel and specify maxcpus/nr_cpus, disable_cpu_apicid=[X]

  options while loading it.



* For s390x there are two kdump modes: If a ELF header is specified with

  the elfcorehdr= kernel parameter, it is used by the kdump kernel as it

  is done on all other architectures. If no elfcorehdr= kernel parameter is