On 11/19/19 12:19, Michael Ellerman wrote: > Qais Yousef <qais.you...@arm.com> writes: > > The core device API performs extra housekeeping bits that are missing > > from directly calling cpu_up/down. > > > > See commit a6717c01ddc2 ("powerpc/rtas: use device model APIs and > > serialization during LPM") for an example description of what might go > > wrong. > > > > This also prepares to make cpu_up/down a private interface for anything > > but the cpu subsystem. > > > > Signed-off-by: Qais Yousef <qais.you...@arm.com> > > CC: Benjamin Herrenschmidt <b...@kernel.crashing.org> > > CC: Paul Mackerras <pau...@samba.org> > > CC: Michael Ellerman <m...@ellerman.id.au> > > CC: Enrico Weigelt <i...@metux.net> > > CC: Ram Pai <linux...@us.ibm.com> > > CC: Nicholas Piggin <npig...@gmail.com> > > CC: Thiago Jung Bauermann <bauer...@linux.ibm.com> > > CC: Christophe Leroy <christophe.le...@c-s.fr> > > CC: Thomas Gleixner <t...@linutronix.de> > > CC: linuxppc-dev@lists.ozlabs.org > > CC: linux-ker...@vger.kernel.org > > --- > > arch/powerpc/kernel/machine_kexec_64.c | 4 +++- > > 1 file changed, 3 insertions(+), 1 deletion(-) > > My initial though is "what about kdump", but that function is not called > during kdump, so there should be no issue with the extra locking leading > to deadlocks in a crash. > > Acked-by: Michael Ellerman <m...@ellerman.id.au>
Thanks. > > I assume you haven't actually tested it? Only compile tested it I'm afraid. Would appreciate if you can give it a spin. Otherwise I'd be happy to try it out on qemu. Cheers -- Qais Yousef