From: Xunlei Pang <xpang@redhat.com>
To: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>, linux-kernel@vger.kernel.org
Cc: bhe@redhat.com, corbet@lwn.net, linux-doc@vger.kernel.org,
kexec@lists.infradead.org, akpm@linux-foundation.org,
dyoung@redhat.com, vgoyal@redhat.com
Subject: Re: [PATCH v7 2/2] Documentation: kdump: add description of enable multi-cpus support
Date: Thu, 18 Aug 2016 10:12:44 +0800 [thread overview]
Message-ID: <57B5199C.3080105@redhat.com> (raw)
In-Reply-To: <1471485011-19035-3-git-send-email-zhouwj-fnst@cn.fujitsu.com>
On 2016/08/18 at 09:50, Zhou Wenjian wrote:
> 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>
> ---
> Documentation/kdump/kdump.txt | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt
> index 96da2b7..c93a6e0 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
> + a SMP dump-capture kernel and specify maxcpus\nr_cpus, disable_cpu_apicid=[X]
s/a SMP/an SMP/
For "maxcpus\nr_cpus", I think to use slash instead of backslash in Linux is better.
Otherwise, looks good to me.
Regards,
Xunlei
> + 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
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WARNING: multiple messages have this Message-ID (diff)
From: Xunlei Pang <xpang@redhat.com>
To: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>, 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
Subject: Re: [PATCH v7 2/2] Documentation: kdump: add description of enable multi-cpus support
Date: Thu, 18 Aug 2016 10:12:44 +0800 [thread overview]
Message-ID: <57B5199C.3080105@redhat.com> (raw)
In-Reply-To: <1471485011-19035-3-git-send-email-zhouwj-fnst@cn.fujitsu.com>
On 2016/08/18 at 09:50, Zhou Wenjian wrote:
> 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>
> ---
> Documentation/kdump/kdump.txt | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt
> index 96da2b7..c93a6e0 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
> + a SMP dump-capture kernel and specify maxcpus\nr_cpus, disable_cpu_apicid=[X]
s/a SMP/an SMP/
For "maxcpus\nr_cpus", I think to use slash instead of backslash in Linux is better.
Otherwise, looks good to me.
Regards,
Xunlei
> + 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
next prev parent reply other threads:[~2016-08-18 2:12 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-18 1:50 [PATCH v7 0/2] update the doc of kdump Zhou Wenjian
2016-08-18 1:50 ` Zhou Wenjian
2016-08-18 1:50 ` [PATCH v7 1/2] Documentation: kdump: remind user of nr_cpus Zhou Wenjian
2016-08-18 1:50 ` Zhou Wenjian
2016-08-18 1:50 ` [PATCH v7 2/2] Documentation: kdump: add description of enable multi-cpus support Zhou Wenjian
2016-08-18 1:50 ` Zhou Wenjian
2016-08-18 2:12 ` Xunlei Pang [this message]
2016-08-18 2:12 ` Xunlei Pang
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