* [PATCH v7 0/2] update the doc of kdump @ 2016-08-18 1:50 ` Zhou Wenjian 0 siblings, 0 replies; 8+ messages in thread From: Zhou Wenjian @ 2016-08-18 1:50 UTC (permalink / raw) To: linux-kernel; +Cc: bhe, corbet, linux-doc, kexec, akpm, dyoung, vgoyal v6->v7: fix typo v5->v6: replace "we" with "you" 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 | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) -- 1.8.3.1 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v7 0/2] update the doc of kdump @ 2016-08-18 1:50 ` Zhou Wenjian 0 siblings, 0 replies; 8+ messages in thread From: Zhou Wenjian @ 2016-08-18 1:50 UTC (permalink / raw) To: linux-kernel; +Cc: akpm, dyoung, bhe, vgoyal, corbet, kexec, linux-doc v6->v7: fix typo v5->v6: replace "we" with "you" 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 | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) -- 1.8.3.1 ^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v7 1/2] Documentation: kdump: remind user of nr_cpus 2016-08-18 1:50 ` Zhou Wenjian @ 2016-08-18 1:50 ` Zhou Wenjian -1 siblings, 0 replies; 8+ messages in thread From: Zhou Wenjian @ 2016-08-18 1:50 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..96da2b7 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, you 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 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v7 1/2] Documentation: kdump: remind user of nr_cpus @ 2016-08-18 1:50 ` Zhou Wenjian 0 siblings, 0 replies; 8+ messages in thread From: Zhou Wenjian @ 2016-08-18 1:50 UTC (permalink / raw) To: linux-kernel; +Cc: akpm, dyoung, bhe, vgoyal, corbet, kexec, linux-doc 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..96da2b7 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, you 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 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v7 2/2] Documentation: kdump: add description of enable multi-cpus support 2016-08-18 1:50 ` Zhou Wenjian @ 2016-08-18 1:50 ` Zhou Wenjian -1 siblings, 0 replies; 8+ messages in thread From: Zhou Wenjian @ 2016-08-18 1:50 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 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] + 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 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v7 2/2] Documentation: kdump: add description of enable multi-cpus support @ 2016-08-18 1:50 ` Zhou Wenjian 0 siblings, 0 replies; 8+ messages in thread From: Zhou Wenjian @ 2016-08-18 1:50 UTC (permalink / raw) To: linux-kernel; +Cc: akpm, dyoung, bhe, vgoyal, corbet, kexec, linux-doc 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] + 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 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH v7 2/2] Documentation: kdump: add description of enable multi-cpus support 2016-08-18 1:50 ` Zhou Wenjian @ 2016-08-18 2:12 ` Xunlei Pang -1 siblings, 0 replies; 8+ messages in thread From: Xunlei Pang @ 2016-08-18 2:12 UTC (permalink / raw) To: Zhou Wenjian, linux-kernel Cc: bhe, corbet, linux-doc, kexec, akpm, dyoung, vgoyal 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 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v7 2/2] Documentation: kdump: add description of enable multi-cpus support @ 2016-08-18 2:12 ` Xunlei Pang 0 siblings, 0 replies; 8+ messages in thread From: Xunlei Pang @ 2016-08-18 2:12 UTC (permalink / raw) To: Zhou Wenjian, linux-kernel Cc: akpm, dyoung, bhe, vgoyal, corbet, kexec, linux-doc 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 ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2016-08-18 2:13 UTC | newest] Thread overview: 8+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 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 2016-08-18 2:12 ` Xunlei Pang
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