diff options
author | Ingo Molnar <mingo@kernel.org> | 2014-07-16 15:10:07 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2014-07-16 15:10:07 +0200 |
commit | d26fad5b38e1c4667d4f2604936e59c837caa54d (patch) | |
tree | 04b524a69a0129c181567445bff18847a1b44721 /kernel/printk/printk.c | |
parent | e720fff6341fe4b95e5a93c939bd3c77fa55ced4 (diff) | |
parent | 1795cd9b3a91d4b5473c97f491d63892442212ab (diff) |
Merge tag 'v3.16-rc5' into sched/core, to refresh the branch before applying bigger tree-wide changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/printk/printk.c')
-rw-r--r-- | kernel/printk/printk.c | 44 |
1 files changed, 18 insertions, 26 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index ea2d5f6962ed..13e839dbca07 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -1416,9 +1416,10 @@ static int have_callable_console(void) /* * Can we actually use the console at this time on this cpu? * - * Console drivers may assume that per-cpu resources have been allocated. So - * unless they're explicitly marked as being able to cope (CON_ANYTIME) don't - * call them until this CPU is officially up. + * Console drivers may assume that per-cpu resources have + * been allocated. So unless they're explicitly marked as + * being able to cope (CON_ANYTIME) don't call them until + * this CPU is officially up. */ static inline int can_use_console(unsigned int cpu) { @@ -1431,10 +1432,8 @@ static inline int can_use_console(unsigned int cpu) * console_lock held, and 'console_locked' set) if it * is successful, false otherwise. */ -static int console_trylock_for_printk(void) +static int console_trylock_for_printk(unsigned int cpu) { - unsigned int cpu = smp_processor_id(); - if (!console_trylock()) return 0; /* @@ -1609,8 +1608,7 @@ asmlinkage int vprintk_emit(int facility, int level, */ if (!oops_in_progress && !lockdep_recursing(current)) { recursion_bug = 1; - local_irq_restore(flags); - return 0; + goto out_restore_irqs; } zap_locks(); } @@ -1718,27 +1716,21 @@ asmlinkage int vprintk_emit(int facility, int level, logbuf_cpu = UINT_MAX; raw_spin_unlock(&logbuf_lock); - lockdep_on(); - local_irq_restore(flags); /* If called from the scheduler, we can not call up(). */ - if (in_sched) - return printed_len; - - /* - * Disable preemption to avoid being preempted while holding - * console_sem which would prevent anyone from printing to console - */ - preempt_disable(); - /* - * Try to acquire and then immediately release the console semaphore. - * The release will print out buffers and wake up /dev/kmsg and syslog() - * users. - */ - if (console_trylock_for_printk()) - console_unlock(); - preempt_enable(); + if (!in_sched) { + /* + * Try to acquire and then immediately release the console + * semaphore. The release will print out buffers and wake up + * /dev/kmsg and syslog() users. + */ + if (console_trylock_for_printk(this_cpu)) + console_unlock(); + } + lockdep_on(); +out_restore_irqs: + local_irq_restore(flags); return printed_len; } EXPORT_SYMBOL(vprintk_emit); |