* [PATCH v5 0/2] update the doc of kdump
@ 2016-08-10 6:22 Zhou Wenjian
2016-08-10 6:22 ` [PATCH v5 1/2] Documentation: kdump: remind user of nr_cpus Zhou Wenjian
2016-08-10 6:22 ` [PATCH v5 2/2] Documentation: kdump: add description of enable multi-cpus support Zhou Wenjian
0 siblings, 2 replies; 5+ messages in thread
From: Zhou Wenjian @ 2016-08-10 6:22 UTC (permalink / raw)
To: linux-kernel; +Cc: bhe, corbet, linux-doc, kexec, akpm, dyoung, vgoyal
v4->v5: move change log to cover letter
v3->v4: update the description of bring up SMP dump-capture kernel
v2->v3: add description of nr_cpus.
v1->v2: change nr_cpus to maxcpus
Zhou Wenjian (2):
Documentation: kdump: remind user of nr_cpus
Documentation: kdump: add description of enable multi-cpus support
Documentation/kdump/kdump.txt | 9 +++++++++
1 file changed, 9 insertions(+)
--
1.8.3.1
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^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v5 1/2] Documentation: kdump: remind user of nr_cpus
2016-08-10 6:22 [PATCH v5 0/2] update the doc of kdump Zhou Wenjian
@ 2016-08-10 6:22 ` Zhou Wenjian
2016-08-10 6:22 ` [PATCH v5 2/2] Documentation: kdump: add description of enable multi-cpus support Zhou Wenjian
1 sibling, 0 replies; 5+ messages in thread
From: Zhou Wenjian @ 2016-08-10 6:22 UTC (permalink / raw)
To: linux-kernel; +Cc: bhe, corbet, linux-doc, kexec, akpm, dyoung, vgoyal
nr_cpus can help to save memory. So we should remind user of it.
Signed-off-by: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>
Acked-by: Baoquan He <bhe@redhat.com>
---
Documentation/kdump/kdump.txt | 2 ++
1 file changed, 2 insertions(+)
diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt
index 88ff63d..b474060 100644
--- a/Documentation/kdump/kdump.txt
+++ b/Documentation/kdump/kdump.txt
@@ -393,6 +393,8 @@ Notes on loading the dump-capture kernel:
* We generally don' have to bring up a SMP kernel just to capture the
dump. Hence generally it is useful either to build a UP dump-capture
kernel or specify maxcpus=1 option while loading dump-capture kernel.
+ Note, though maxcpus always works, we should replace it by nr_cpus to
+ save memory if supported by the current ARCH, such as x86.
* 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
--
1.8.3.1
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^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v5 2/2] Documentation: kdump: add description of enable multi-cpus support
2016-08-10 6:22 [PATCH v5 0/2] update the doc of kdump Zhou Wenjian
2016-08-10 6:22 ` [PATCH v5 1/2] Documentation: kdump: remind user of nr_cpus Zhou Wenjian
@ 2016-08-10 6:22 ` Zhou Wenjian
2016-08-10 9:16 ` Dave Young
1 sibling, 1 reply; 5+ messages in thread
From: Zhou Wenjian @ 2016-08-10 6:22 UTC (permalink / raw)
To: linux-kernel; +Cc: bhe, corbet, linux-doc, kexec, akpm, dyoung, vgoyal
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 b474060..9c8d18e 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, we should replace it by nr_cpus to
save memory if supported by the current ARCH, such as x86.
+* We should enable multi-cpu support in dump-capture kernel if we 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, we should bring up
+ a SMP dump-capture kernel and specify maxcpus\nr_cpus, disable_cpu_apic=[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
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^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v5 2/2] Documentation: kdump: add description of enable multi-cpus support
2016-08-10 6:22 ` [PATCH v5 2/2] Documentation: kdump: add description of enable multi-cpus support Zhou Wenjian
@ 2016-08-10 9:16 ` Dave Young
0 siblings, 0 replies; 5+ messages in thread
From: Dave Young @ 2016-08-10 9:16 UTC (permalink / raw)
To: Zhou Wenjian; +Cc: linux-kernel, akpm, bhe, vgoyal, corbet, kexec, linux-doc
On 08/10/16 at 02:22pm, 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 b474060..9c8d18e 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, we should replace it by nr_cpus to
> save memory if supported by the current ARCH, such as x86.
>
> +* We should enable multi-cpu support in dump-capture kernel if we 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, we should bring up
> + a SMP dump-capture kernel and specify maxcpus\nr_cpus, disable_cpu_apic=[X]
> + options while loading it.
Again, please replace "we" with second person "you"..
> +
> * 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
>
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v5 2/2] Documentation: kdump: add description of enable multi-cpus support
@ 2016-08-10 9:16 ` Dave Young
0 siblings, 0 replies; 5+ messages in thread
From: Dave Young @ 2016-08-10 9:16 UTC (permalink / raw)
To: Zhou Wenjian; +Cc: bhe, corbet, linux-doc, kexec, linux-kernel, akpm, vgoyal
On 08/10/16 at 02:22pm, 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 b474060..9c8d18e 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, we should replace it by nr_cpus to
> save memory if supported by the current ARCH, such as x86.
>
> +* We should enable multi-cpu support in dump-capture kernel if we 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, we should bring up
> + a SMP dump-capture kernel and specify maxcpus\nr_cpus, disable_cpu_apic=[X]
> + options while loading it.
Again, please replace "we" with second person "you"..
> +
> * 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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end of thread, other threads:[~2016-08-10 18:43 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2016-08-10 6:22 [PATCH v5 0/2] update the doc of kdump Zhou Wenjian
2016-08-10 6:22 ` [PATCH v5 1/2] Documentation: kdump: remind user of nr_cpus Zhou Wenjian
2016-08-10 6:22 ` [PATCH v5 2/2] Documentation: kdump: add description of enable multi-cpus support Zhou Wenjian
2016-08-10 9:16 ` Dave Young
2016-08-10 9:16 ` Dave Young
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