diff options
| author | Helge Deller <deller@gmx.de> | 2022-03-27 16:03:53 +0300 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2022-03-29 22:37:13 +0300 |
| commit | 1afde47d082c92c4fd3d9b322d944f8d87469834 (patch) | |
| tree | 8e7cd0280a22b7dfdc7e1af3691106e9172109f9 /arch/parisc | |
| parent | ca45ec3cb44aabe0933f9e10dba1b6946afb2a13 (diff) | |
| download | linux-1afde47d082c92c4fd3d9b322d944f8d87469834.tar.xz | |
parisc: Find a new timesync master if current CPU is removed
When CPU hotplugging is enabled, the user may want to remove the
current CPU which is providing the timer ticks. If this happens
we need to find a new timesync master.
Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to 'arch/parisc')
| -rw-r--r-- | arch/parisc/include/asm/processor.h | 1 | ||||
| -rw-r--r-- | arch/parisc/kernel/smp.c | 6 | ||||
| -rw-r--r-- | arch/parisc/kernel/time.c | 4 |
3 files changed, 10 insertions, 1 deletions
diff --git a/arch/parisc/include/asm/processor.h b/arch/parisc/include/asm/processor.h index 006364212795..4621ceb51314 100644 --- a/arch/parisc/include/asm/processor.h +++ b/arch/parisc/include/asm/processor.h @@ -95,6 +95,7 @@ struct cpuinfo_parisc { extern struct system_cpuinfo_parisc boot_cpu_data; DECLARE_PER_CPU(struct cpuinfo_parisc, cpu_data); +extern int time_keeper_id; /* CPU used for timekeeping */ #define CPU_HVERSION ((boot_cpu_data.hversion >> 4) & 0x0FFF) diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c index 8c5ea457b6e1..24d0744c3b3a 100644 --- a/arch/parisc/kernel/smp.c +++ b/arch/parisc/kernel/smp.c @@ -465,6 +465,12 @@ int __cpu_disable(void) */ set_cpu_online(cpu, false); + /* Find a new timesync master */ + if (cpu == time_keeper_id) { + time_keeper_id = cpumask_first(cpu_online_mask); + pr_info("CPU %d is now promoted to time-keeper master\n", time_keeper_id); + } + disable_percpu_irq(IPI_IRQ); irq_migrate_all_off_this_cpu(); diff --git a/arch/parisc/kernel/time.c b/arch/parisc/kernel/time.c index 874b128c5783..bb27dfeeddfc 100644 --- a/arch/parisc/kernel/time.c +++ b/arch/parisc/kernel/time.c @@ -40,6 +40,8 @@ #include <linux/timex.h> +int time_keeper_id __read_mostly; /* CPU used for timekeeping. */ + static unsigned long clocktick __ro_after_init; /* timer cycles per tick */ /* @@ -84,7 +86,7 @@ irqreturn_t __irq_entry timer_interrupt(int irq, void *dev_id) cpuinfo->it_value = next_tick; /* Go do system house keeping. */ - if (cpu != 0) + if (IS_ENABLED(CONFIG_SMP) && (cpu != time_keeper_id)) ticks_elapsed = 0; legacy_timer_tick(ticks_elapsed); |