From 82689ac663ac2f3fe89231b2f929fbdae178bb81 Mon Sep 17 00:00:00 2001 From: Dengcheng Zhu Date: Wed, 26 Sep 2018 19:49:10 +0000 Subject: MIPS: kdump: Mark cpu back online before rebooting The crash utility initializes cpu state by reading the system kernel memory, which is copied into vmcore. It is also natural to preserve the online state for CPUs at crash. Failing to do so could make the analysis tool present info for only 1 CPU by default, and unable to find panic task. Signed-off-by: Dengcheng Zhu Signed-off-by: Paul Burton Patchwork: https://patchwork.linux-mips.org/patch/20809/ Cc: Paul Burton Cc: "ralf@linux-mips.org" Cc: "linux-mips@linux-mips.org" Cc: "rachel.mozes@intel.com" --- arch/mips/kernel/machine_kexec.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'arch/mips/kernel/machine_kexec.c') diff --git a/arch/mips/kernel/machine_kexec.c b/arch/mips/kernel/machine_kexec.c index 35175eb2e8b0..93936dce04d6 100644 --- a/arch/mips/kernel/machine_kexec.c +++ b/arch/mips/kernel/machine_kexec.c @@ -173,6 +173,16 @@ void kexec_reboot(void) { void (*do_kexec)(void) __noreturn; + /* + * We know we were online, and there will be no incoming IPIs at + * this point. Mark online again before rebooting so that the crash + * analysis tool will see us correctly. + */ + set_cpu_online(smp_processor_id(), true); + + /* Ensure remote CPUs observe that we're online before rebooting. */ + smp_mb__after_atomic(); + #ifdef CONFIG_SMP if (smp_processor_id() > 0) { /* -- cgit v1.2.3