Hi Akashi, On 07/09/16 05:29, AKASHI Takahiro wrote: > This patch adds arch specific descriptions about kdump usage on arm64 > to kdump.txt. > diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt > @@ -249,6 +249,13 @@ Dump-capture kernel config options (Arch Dependent, arm) > > AUTO_ZRELADDR=y > > +Dump-capture kernel config options (Arch Dependent, arm64) > +---------------------------------------------------------- > + > +- Please note that kvm of the dump-capture kernel will not be enabled > + on non-VHE systems even if it is configured. This is because the CPU > + cannot be reset to EL2 on panic. Nit: cannot be -> will not be We could try to do this, but its more code that could prevent us reaching the kdump kernel, so we choose not to. > @@ -370,6 +381,9 @@ For s390x: > For arm: > "1 maxcpus=1 reset_devices" > > +For arm64: > + "1 maxcpus=1 reset_devices" > + 'maxcpus=1' is a bit fragile. Since 44dbcc93ab67145 ("arm64: Fix behavior of maxcpus=N") udev on ubuntu vivid (running on Juno) has taken it upon itself to bring the secondary cores online, even when booted with 'maxcpus=1'. Can we change the recomendation to "1 nosmp reset_devices"? Thanks, James