diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2012-09-19 14:50:37 +0200 |
|---|---|---|
| committer | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2016-02-13 00:36:24 +0100 |
| commit | 8b243b07a24ba4fbfa77d301efc5fad6f0dae3fa (patch) | |
| tree | f745bf369e8b21daa102e5d692b78c0883e92f77 | |
| parent | a6d7965037905e3ddf1b43be0bb29de8b87b132a (diff) | |
| download | rt-linux-8b243b07a24ba4fbfa77d301efc5fad6f0dae3fa.tar.gz | |
printk: Make rt aware
Drop the lock before calling the console driver and do not disable
interrupts while printing to a serial console.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | kernel/printk/printk.c | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index e0961954c00243..763af49002fc08 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -1502,6 +1502,7 @@ static void call_console_drivers(int level, if (!console_drivers) return; + migrate_disable(); for_each_console(con) { if (exclusive_console && con != exclusive_console) continue; @@ -1517,6 +1518,7 @@ static void call_console_drivers(int level, else con->write(con, text, len); } + migrate_enable(); } /* @@ -1577,6 +1579,15 @@ static inline int can_use_console(unsigned int cpu) static int console_trylock_for_printk(void) { unsigned int cpu = smp_processor_id(); +#ifdef CONFIG_PREEMPT_RT_FULL + int lock = !early_boot_irqs_disabled && (preempt_count() == 0) && + !irqs_disabled(); +#else + int lock = 1; +#endif + + if (!lock) + return 0; if (!console_trylock()) return 0; @@ -1879,8 +1890,7 @@ asmlinkage int vprintk_emit(int facility, int level, * console_sem which would prevent anyone from printing to * console */ - preempt_disable(); - + migrate_disable(); /* * Try to acquire and then immediately release the console * semaphore. The release will print out buffers and wake up @@ -1888,7 +1898,7 @@ asmlinkage int vprintk_emit(int facility, int level, */ if (console_trylock_for_printk()) console_unlock(); - preempt_enable(); + migrate_enable(); lockdep_on(); } @@ -2248,11 +2258,16 @@ static void console_cont_flush(char *text, size_t size) goto out; len = cont_print_text(text, size); +#ifdef CONFIG_PREEMPT_RT_FULL + raw_spin_unlock_irqrestore(&logbuf_lock, flags); + call_console_drivers(cont.level, NULL, 0, text, len); +#else raw_spin_unlock(&logbuf_lock); stop_critical_timings(); call_console_drivers(cont.level, NULL, 0, text, len); start_critical_timings(); local_irq_restore(flags); +#endif return; out: raw_spin_unlock_irqrestore(&logbuf_lock, flags); @@ -2351,12 +2366,17 @@ skip: console_idx = log_next(console_idx); console_seq++; console_prev = msg->flags; +#ifdef CONFIG_PREEMPT_RT_FULL + raw_spin_unlock_irqrestore(&logbuf_lock, flags); + call_console_drivers(level, ext_text, ext_len, text, len); +#else raw_spin_unlock(&logbuf_lock); stop_critical_timings(); /* don't trace print latency */ call_console_drivers(level, ext_text, ext_len, text, len); start_critical_timings(); local_irq_restore(flags); +#endif } console_locked = 0; |