diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2012-09-19 12:50:37 (GMT) |
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committer | Scott Wood <scottwood@freescale.com> | 2013-04-04 22:09:31 (GMT) |
commit | 00c59821fe6309ba22590cbe2a93e2b769bb8c4f (patch) | |
tree | 5c0d02b47f65d5c3d9bdac913b56cf8a872196e1 /kernel | |
parent | c257932f43b73f6a414e9dbb0f4be0dadfd3665a (diff) | |
download | linux-fsl-qoriq-00c59821fe6309ba22590cbe2a93e2b769bb8c4f.tar.xz |
printk-rt-aware.patch
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/printk.c | 33 |
1 files changed, 29 insertions, 4 deletions
diff --git a/kernel/printk.c b/kernel/printk.c index df4b56b..2609082 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -1315,6 +1315,7 @@ static void call_console_drivers(int level, const char *text, size_t len) if (!console_drivers) return; + migrate_disable(); for_each_console(con) { if (exclusive_console && con != exclusive_console) continue; @@ -1327,6 +1328,7 @@ static void call_console_drivers(int level, const char *text, size_t len) continue; con->write(con, text, len); } + migrate_enable(); } /* @@ -1386,12 +1388,18 @@ static inline int can_use_console(unsigned int cpu) * interrupts disabled. It should return with 'lockbuf_lock' * released but interrupts still disabled. */ -static int console_trylock_for_printk(unsigned int cpu) +static int console_trylock_for_printk(unsigned int cpu, unsigned long flags) __releases(&logbuf_lock) { int retval = 0, wake = 0; +#ifdef CONFIG_PREEMPT_RT_FULL + int lock = !early_boot_irqs_disabled && !irqs_disabled_flags(flags) && + (preempt_count() <= 1); +#else + int lock = 1; +#endif - if (console_trylock()) { + if (lock && console_trylock()) { retval = 1; /* @@ -1670,8 +1678,15 @@ asmlinkage int vprintk_emit(int facility, int level, * The console_trylock_for_printk() function will release 'logbuf_lock' * regardless of whether it actually gets the console semaphore or not. */ - if (console_trylock_for_printk(this_cpu)) + if (console_trylock_for_printk(this_cpu, flags)) { +#ifndef CONFIG_PREEMPT_RT_FULL + console_unlock(); +#else + raw_local_irq_restore(flags); console_unlock(); + raw_local_irq_save(flags); +#endif + } lockdep_on(); out_restore_irqs: @@ -2060,11 +2075,16 @@ static void console_cont_flush(char *text, size_t size) goto out; len = cont_print_text(text, size); +#ifndef CONFIG_PREEMPT_RT_FULL raw_spin_unlock(&logbuf_lock); stop_critical_timings(); call_console_drivers(cont.level, text, len); start_critical_timings(); local_irq_restore(flags); +#else + raw_spin_unlock_irqrestore(&logbuf_lock, flags); + call_console_drivers(cont.level, text, len); +#endif return; out: raw_spin_unlock_irqrestore(&logbuf_lock, flags); @@ -2147,12 +2167,17 @@ skip: console_idx = log_next(console_idx); console_seq++; console_prev = msg->flags; - raw_spin_unlock(&logbuf_lock); +#ifndef CONFIG_PREEMPT_RT_FULL + raw_spin_unlock(&logbuf_lock); stop_critical_timings(); /* don't trace print latency */ call_console_drivers(level, text, len); start_critical_timings(); local_irq_restore(flags); +#else + raw_spin_unlock_irqrestore(&logbuf_lock, flags); + call_console_drivers(level, text, len); +#endif } console_locked = 0; |