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[PATCH v2] Documentation: kdump: add description of bringing up SMP dump-capture kernel

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v1->v2: change nr_cpus to maxcpus

SMP dump-capture kernel is useful to improve the performance of kdump in
some cases. So add the description of bringing up SMP dump-capture kernel.

Signed-off-by: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>
---
 Documentation/kdump/kdump.txt | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt
index 88ff63d..c5762b7 100644
--- a/Documentation/kdump/kdump.txt
+++ b/Documentation/kdump/kdump.txt
@@ -394,6 +394,12 @@ Notes on loading the dump-capture kernel:
   dump. Hence generally it is useful either to build a UP dump-capture
   kernel or specify maxcpus=1 option while loading dump-capture kernel.
 
+* We should bring up a SMP dump-capture kernel if we intend to use multi-threads
+  programs with it, such as parallel dump feature of makedumpfile. Otherwise,
+  the multi-threads program may have a great performance degradation.
+  To bring up a SMP dump-capture kernel, we should specify maxcpus=[X] and
+  disable_cpu_apic=[Y] 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
-- 
1.8.3.1

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[PATCH v2] Documentation: kdump: add description of bringing up SMP dump-capture kernel Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com> - 2016-08-01 02:30 +0200
  Re: [PATCH v2] Documentation: kdump: add description of bringing up  SMP dump-capture kernel Baoquan He <bhe@redhat.com> - 2016-08-02 10:00 +0200
    Re: [PATCH v2] Documentation: kdump: add description of bringing  up SMP dump-capture kernel "Zhou, Wenjian/周文剑"   <zhouwj-fnst@cn.fujitsu.com> - 2016-08-02 11:10 +0200
      Re: [PATCH v2] Documentation: kdump: add description of bringing up  SMP dump-capture kernel Baoquan He <bhe@redhat.com> - 2016-08-02 16:30 +0200

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