On Sat 2016-04-23 12:49:24, Sergey Senozhatsky wrote:
> Hello Petr,
>
> On (04/21/16 13:48), Petr Mladek wrote:
> > extern void printk_nmi_flush(void);
> > +extern void printk_nmi_flush_on_panic(void);
> > #else
> > static inline void printk_nmi_flush(void) { }
> > +static inline void printk_nmi_flush_on_panic(void) { }
> [..]
> > +void printk_nmi_flush_on_panic(void)
> > +{
> > + /*
> > + * Make sure that we could access the main ring buffer.
> > + * Do not risk a double release when more CPUs are up.
> > + */
> > + if (in_nmi() && raw_spin_is_locked(&logbuf_lock)) {
> > + if (num_online_cpus() > 1)
> > + return;
> > +
> > + debug_locks_off();
> > + raw_spin_lock_init(&logbuf_lock);
> > + }
> > +
> > + printk_nmi_flush();
> > +}
> [..]
> > -static DEFINE_RAW_SPINLOCK(logbuf_lock);
> > +DEFINE_RAW_SPINLOCK(logbuf_lock);
>
> just an idea,
>
> how about doing it a bit differently?
>
>
> move printk_nmi_flush_on_panic() to printk.c, and place it next to
> printk_flush_on_panic() (so we will have two printk "flush-on-panic"
> functions sitting together). /* printk_nmi_flush() is in printk.h,
> so it's visible to printk anyway */
>
> it also will let us keep logbuf_lock static, it's a bit too internal
> to printk to expose it, I think.
>
> IOW, something like this?
It is rather cosmetic change. I
> ---
>
> kernel/printk/internal.h | 2 --
> kernel/printk/nmi.c | 27 ---------------------------
> kernel/printk/printk.c | 29 ++++++++++++++++++++++++++++-
> 3 files changed, 28 insertions(+), 30 deletions(-)
>
> diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h
> index 7fd2838..341bedc 100644
> --- a/kernel/printk/internal.h
> +++ b/kernel/printk/internal.h
> @@ -22,8 +22,6 @@ int __printf(1, 0) vprintk_default(const char *fmt, va_list args);
>
> #ifdef CONFIG_PRINTK_NMI
>
> -extern raw_spinlock_t logbuf_lock;
Well, it was exposed only in the internal.h header file. I consider
this rather a cosmetic change and do not have strong opinion about it. :-)
Anyway, thanks a lot for review.
Best Regards,
Petr
