From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Tue, 15 Dec 2015 17:05:24 +0000 Subject: [PATCH v12 16/16] arm64: kdump: relax BUG_ON() if more than one cpus are still active In-Reply-To: <83db66df70fc1f7cd4da8b580d264b9320991cf0.1448403503.git.geoff@infradead.org> References: <83db66df70fc1f7cd4da8b580d264b9320991cf0.1448403503.git.geoff@infradead.org> Message-ID: <20151215170523.GA353@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Nov 24, 2015 at 10:25:34PM +0000, Geoff Levand wrote: > From: AKASHI Takahiro > > We should try best in case of kdump. > So even if not all secondary cpus have shut down, we do kdump anyway. > --- > arch/arm64/kernel/machine_kexec.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c > index d2d7e90..482aae7 100644 > --- a/arch/arm64/kernel/machine_kexec.c > +++ b/arch/arm64/kernel/machine_kexec.c > @@ -148,7 +148,13 @@ void machine_kexec(struct kimage *kimage) > phys_addr_t reboot_code_buffer_phys; > void *reboot_code_buffer; > > - BUG_ON(num_online_cpus() > 1); > + if (num_online_cpus() > 1) { > + if (in_crash_kexec) > + pr_warn("kdump might fail because %d cpus are still online\n", > + num_online_cpus()); > + else > + BUG(); > + } Can you just rewrite the existing BUG_ON as: BUG_ON(num_online_cpus() && !WARN_ON(in_crash_kexec)); ? Will