Messages in this thread | | | From | Paul Gortmaker <> | Date | Thu, 14 Mar 2013 18:24:22 -0400 | Subject | Re: [PATCH 2/2] printk: Provide a wake_up_klogd() off-case |
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On Thu, Mar 14, 2013 at 4:39 PM, Andrew Morton <akpm@linux-foundation.org> wrote: > On Thu, 14 Mar 2013 15:26:29 +0100 Frederic Weisbecker <fweisbec@gmail.com> wrote: > >> wake_up_klogd() is useless when CONFIG_PRINTK=n because >> neither printk() nor printk_sched() are in use and there >> are actually no waiter on log_wait waitqueue. It should >> be a stub in this case for users like bust_spinlocks(). >> >> Otherwise this results in this warning when CONFIG_PRINTK=n >> and CONFIG_IRQ_WORK=n: >> >> kernel/built-in.o In function `wake_up_klogd': >> (.text.wake_up_klogd+0xb4): undefined reference to `irq_work_queue' >> >> To fix this, provide an off-case for wake_up_klogd() when >> CONFIG_PRINTK=n. >> >> There is much more from console_unlock() and other console >> related code in printk.c that should be moved under >> CONFIG_PRINTK. But for now, focus on a minimal fix as we passed >> the merged window already. >> >> --- a/include/linux/kernel.h >> +++ b/include/linux/kernel.h >> @@ -390,7 +390,6 @@ extern struct pid *session_of_pgrp(struct pid *pgrp); >> unsigned long int_sqrt(unsigned long); >> >> extern void bust_spinlocks(int yes); >> -extern void wake_up_klogd(void); >> extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */ >> extern int panic_timeout; >> extern int panic_on_oops; >> diff --git a/include/linux/printk.h b/include/linux/printk.h >> index 1249a54..822171f 100644 >> --- a/include/linux/printk.h >> +++ b/include/linux/printk.h >> @@ -134,6 +134,8 @@ extern int printk_delay_msec; >> extern int dmesg_restrict; >> extern int kptr_restrict; >> >> +extern void wake_up_klogd(void); >> + > > Given this, it would be prudent to include printk.h in > bust_spinlocks.c. printk.h currently gets included by kernel.h, but > that doesn't actually seem necessary - nothing in kernel.h calls > printk(). > > (I pity anyone who tries to remove that include from kernel.h ;))
Why did you have to say that? Now I'm inclined to poke at it and just see how bad it really is when I pull on that loose thread...
P. --
> > --- a/lib/bust_spinlocks.c~printk-provide-a-wake_up_klogd-off-case-fix > +++ a/lib/bust_spinlocks.c > @@ -8,6 +8,7 @@ > */ > > #include <linux/kernel.h> > +#include <linux/printk.h> > #include <linux/spinlock.h> > #include <linux/tty.h> > #include <linux/wait.h> > @@ -28,5 +29,3 @@ void __attribute__((weak)) bust_spinlock > wake_up_klogd(); > } > } > - > - > _ > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
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