From: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>
To: <linux-kernel@vger.kernel.org>
Cc: <akpm@linux-foundation.org>, <dyoung@redhat.com>,
<bhe@redhat.com>, <vgoyal@redhat.com>, <corbet@lwn.net>,
<kexec@lists.infradead.org>, <linux-doc@vger.kernel.org>,
<xlpang@redhat.com>, <joe@perches.com>
Subject: [PATCH v9 2/2] Documentation: kdump: add description of enable multi-cpus support
Date: Thu, 18 Aug 2016 11:11:47 +0800 [thread overview]
Message-ID: <1471489907-27737-3-git-send-email-zhouwj-fnst@cn.fujitsu.com> (raw)
In-Reply-To: <1471489907-27737-1-git-send-email-zhouwj-fnst@cn.fujitsu.com>
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: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Xunlei Pang <xpang@redhat.com>
---
Documentation/kdump/kdump.txt | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt
index d900080..31e6b88 100644
--- a/Documentation/kdump/kdump.txt
+++ b/Documentation/kdump/kdump.txt
@@ -396,6 +396,13 @@ Notes on loading the dump-capture kernel:
Note, though maxcpus always works, you should replace it by 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
--
1.8.3.1
prev parent reply other threads:[~2016-08-18 3:13 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-18 3:11 [PATCH v9 0/2] update the doc of kdump Zhou Wenjian
2016-08-18 3:11 ` [PATCH v9 1/2] Documentation: kdump: remind user of nr_cpus Zhou Wenjian
2016-08-18 17:18 ` Jonathan Corbet
2016-08-19 0:33 ` "Zhou, Wenjian/周文剑"
2016-08-19 15:57 ` Jonathan Corbet
2016-08-22 1:14 ` "Zhou, Wenjian/周文剑"
2016-08-24 5:06 ` Baoquan He
2016-08-25 19:10 ` Jonathan Corbet
2016-08-27 0:35 ` Baoquan He
2016-08-26 0:45 ` "Zhou, Wenjian/周文剑"
2016-08-27 0:38 ` Baoquan He
2016-08-18 3:11 ` Zhou Wenjian [this message]
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