From: Baoquan He <bhe@redhat.com>
To: corbet@lwn.net, akpm@linux-foundation.org
Cc: linux-doc@vger.kernel.org, kexec@lists.infradead.org,
Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>,
xlpang@redhat.com, linux-kernel@vger.kernel.org,
dyoung@redhat.com
Subject: [PATCH v10 RESEND 3/3] Documentation: kdump: Add description of enable multi-cpus support
Date: Mon, 19 Sep 2016 13:59:49 +0800 [thread overview]
Message-ID: <1474264789-11705-4-git-send-email-bhe@redhat.com> (raw)
In-Reply-To: <1474264789-11705-1-git-send-email-bhe@redhat.com>
From: Zhou Wenjian <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 f7ef340..b0eb27b 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 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
--
2.5.5
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next prev parent reply other threads:[~2016-09-19 6:00 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-19 5:59 [PATCH v10 RESEND 0/3] Documentation: Add description of enable multi-cpus support for kdump Baoquan He
2016-09-19 5:59 ` [PATCH v10 RESEND 1/3] docs: kernel-parameter : Improve the description of nr_cpus and maxcpus Baoquan He
2016-09-19 5:59 ` [PATCH v10 RESEND 2/3] Documentation: kdump: Remind user of nr_cpus Baoquan He
2016-09-19 5:59 ` Baoquan He [this message]
2016-09-21 0:03 ` [PATCH v10 RESEND 0/3] Documentation: Add description of enable multi-cpus support for kdump Jonathan Corbet
2016-09-21 1:20 ` Baoquan He
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