diff options
| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2014-12-11 09:12:01 -0500 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2014-12-11 09:12:01 -0500 |
| commit | 1fb8915b9876a80f43732980208b39d013f8da9d (patch) | |
| tree | 73a82f42c9601dd1155092ff7283476fe9d625e6 /kernel/printk | |
| parent | db0865543739b3edb2ee9bf340380cf4986b58ff (diff) | |
| download | blackbird-op-linux-1fb8915b9876a80f43732980208b39d013f8da9d.tar.gz blackbird-op-linux-1fb8915b9876a80f43732980208b39d013f8da9d.zip | |
printk: Do not disable preemption for accessing printk_func
As printk_func will either be the default function, or a per_cpu function
for the current CPU, there's no reason to disable preemption to access
it from printk. That's because if the printk_func is not the default
then the caller had better disabled preemption as they were the one to
change it.
Link: http://lkml.kernel.org/r/CA+55aFz5-_LKW4JHEBoWinN9_ouNcGRWAF2FUA35u46FRN-Kxw@mail.gmail.com
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/printk')
| -rw-r--r-- | kernel/printk/printk.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 5af2b8bc88f0..9b896e7a50a9 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -1859,10 +1859,16 @@ asmlinkage __visible int printk(const char *fmt, ...) int r; va_start(args, fmt); - preempt_disable(); + + /* + * If a caller overrides the per_cpu printk_func, then it needs + * to disable preemption when calling printk(). Otherwise + * the printk_func should be set to the default. No need to + * disable preemption here. + */ vprintk_func = this_cpu_read(printk_func); r = vprintk_func(fmt, args); - preempt_enable(); + va_end(args); return r; |
