Messages in this thread Patch in this message | | | From | Pingfan Liu <> | Subject | [RFC 04/10] cpu/hotplug: Check the capability of kexec quick reboot | Date | Mon, 22 Aug 2022 10:15:14 +0800 |
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The kexec quick reboot needs each involved cpuhp_step to run in parallel.
There are lots of teardown cpuhp_step, but not all of them belong to arm/arm64/riscv kexec reboot path. So introducing a member 'support_kexec_parallel' in the struct cpuhp_step to signal whether the teardown supports parallel or not. If a cpuhp_step is used in kexec reboot, then it needs to support parallel to enable the quick reboot.
The function check_quick_reboot() checks all teardown cpuhp_steps and report those unsupported if any.
Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Steven Price <steven.price@arm.com> Cc: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> To: linux-arm-kernel@lists.infradead.org To: linux-ia64@vger.kernel.org To: linux-riscv@lists.infradead.org To: linux-kernel@vger.kernel.org --- include/linux/cpuhotplug.h | 2 ++ kernel/cpu.c | 28 +++++++++++++++++++++++++++- 2 files changed, 29 insertions(+), 1 deletion(-)
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index f61447913db9..73093fc15aec 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -374,6 +374,8 @@ static inline int cpuhp_setup_state_multi(enum cpuhp_state state, (void *) teardown, true); } +void cpuhp_set_step_parallel(enum cpuhp_state state); + int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node, bool invoke); int __cpuhp_state_add_instance_cpuslocked(enum cpuhp_state state, diff --git a/kernel/cpu.c b/kernel/cpu.c index 94ab2727d6bb..1261c3f3be51 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -137,6 +137,9 @@ struct cpuhp_step { /* public: */ bool cant_stop; bool multi_instance; +#ifdef CONFIG_SHUTDOWN_NONBOOT_CPUS + bool support_kexec_parallel; +#endif }; static DEFINE_MUTEX(cpuhp_state_mutex); @@ -147,6 +150,14 @@ static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state) return cpuhp_hp_states + state; } +#ifdef CONFIG_SHUTDOWN_NONBOOT_CPUS +void cpuhp_set_step_parallel(enum cpuhp_state state) +{ + cpuhp_hp_states[state].support_kexec_parallel = true; +} +EXPORT_SYMBOL(cpuhp_set_step_parallel); +#endif + static bool cpuhp_step_empty(bool bringup, struct cpuhp_step *step) { return bringup ? !step->startup.single : !step->teardown.single; @@ -1347,7 +1358,22 @@ static void takedown_cpus_no_rollback(struct cpumask *cpus) static bool check_quick_reboot(void) { - return false; + struct cpuhp_step *step; + enum cpuhp_state state; + bool ret = true; + + for (state = CPUHP_ONLINE; state >= CPUHP_AP_OFFLINE; state--) { + step = cpuhp_get_step(state); + if (step->teardown.single == NULL) + continue; + if (step->support_kexec_parallel == false) { + pr_info("cpuhp state:%d, %s, does not support cpudown in parallel\n", + state, step->name); + ret = false; + } + } + + return ret; } static struct cpumask kexec_ap_map; -- 2.31.1
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