From: Baoquan He <bhe@redhat.com> To: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com> Cc: linux-kernel@vger.kernel.org, dyoung@redhat.com, d.hatayama@jp.fujitsu.com, kexec@lists.infradead.org Subject: Re: [PATCH v3 2/2] Documentation: kdump: add description of bringing up SMP dump-capture kernel Date: Wed, 3 Aug 2016 09:58:18 +0800 [thread overview] Message-ID: <20160803015818.GB2465@x1.redhat.com> (raw) In-Reply-To: <1470185952-23477-2-git-send-email-zhouwj-fnst@cn.fujitsu.com> On 08/03/16 at 08:59am, Zhou Wenjian wrote: > SMP dump-capture kernel is useful to improve the performance of kdump in > some cases. So add the description of bringing up SMP dump-capture kernel. > > Signed-off-by: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com> > --- > Documentation/kdump/kdump.txt | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt > index 4aa194e..948b42d 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 bring up a SMP dump-capture kernel if we intend to use Well, here about SMP dump-capture kernel do you mean kdump kernel with multi-cpu? If I understand it correctly, it's still SMP kdump kernel though nr_cpus=1 is specified. > + multi-threads programs with it, such as parallel dump feature of > + makedumpfile. Otherwise, the multi-threads program may have a great > + performance degradation. To bring up a SMP dump-capture kernel, we > + should specify maxcpus\nr_cpus and 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 > > > > > _______________________________________________ > kexec mailing list > kexec@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec
WARNING: multiple messages have this Message-ID (diff)
From: Baoquan He <bhe@redhat.com> To: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com> Cc: kexec@lists.infradead.org, d.hatayama@jp.fujitsu.com, dyoung@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 2/2] Documentation: kdump: add description of bringing up SMP dump-capture kernel Date: Wed, 3 Aug 2016 09:58:18 +0800 [thread overview] Message-ID: <20160803015818.GB2465@x1.redhat.com> (raw) In-Reply-To: <1470185952-23477-2-git-send-email-zhouwj-fnst@cn.fujitsu.com> On 08/03/16 at 08:59am, Zhou Wenjian wrote: > SMP dump-capture kernel is useful to improve the performance of kdump in > some cases. So add the description of bringing up SMP dump-capture kernel. > > Signed-off-by: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com> > --- > Documentation/kdump/kdump.txt | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt > index 4aa194e..948b42d 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 bring up a SMP dump-capture kernel if we intend to use Well, here about SMP dump-capture kernel do you mean kdump kernel with multi-cpu? If I understand it correctly, it's still SMP kdump kernel though nr_cpus=1 is specified. > + multi-threads programs with it, such as parallel dump feature of > + makedumpfile. Otherwise, the multi-threads program may have a great > + performance degradation. To bring up a SMP dump-capture kernel, we > + should specify maxcpus\nr_cpus and 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 > > > > > _______________________________________________ > kexec mailing list > kexec@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2016-08-03 1:58 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-08-03 0:59 [PATCH v3 1/2] Documentation: kdump: remind user of nr_cpus Zhou Wenjian 2016-08-03 0:59 ` Zhou Wenjian 2016-08-03 0:59 ` [PATCH v3 2/2] Documentation: kdump: add description of bringing up SMP dump-capture kernel Zhou Wenjian 2016-08-03 0:59 ` Zhou Wenjian 2016-08-03 1:58 ` Baoquan He [this message] 2016-08-03 1:58 ` Baoquan He 2016-08-03 2:05 ` "Zhou, Wenjian/周文剑" 2016-08-03 2:05 ` "Zhou, Wenjian/周文剑" 2016-08-03 2:18 ` Baoquan He 2016-08-03 2:18 ` Baoquan He 2016-08-03 2:19 ` "Zhou, Wenjian/周文剑" 2016-08-03 2:19 ` "Zhou, Wenjian/周文剑" 2016-08-03 1:23 ` [PATCH v3 1/2] Documentation: kdump: remind user of nr_cpus Baoquan He 2016-08-03 1:23 ` Baoquan He 2016-08-08 2:14 ` Dave Young 2016-08-08 2:14 ` Dave Young
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