On Wed, Aug 23, 2017 at 02:55:17PM +0900, Sergey Senozhatsky wrote: > On (08/23/17 13:35), Boqun Feng wrote: > > > KERN_CONT and "\n" should not be together. "\n" flushes the cont > > > buffer immediately. > > > > > > > Hmm.. Not quite familiar with printk() stuffs, but I could see several > > usages of printk(KERN_CONT "...\n") in kernel. > > > > Did a bit research myself, and I now think the inappropriate use is to > > use a KERN_CONT printk *after* another printk ending with a "\n". > > ah... I didn't check __print_lock_name(): it leaves unflushed cont buffer > upon the return. sorry, your code is correct. >
So means printk(KERN_CON "..."); + printk(KERN_CONT "...\n") is a
correct usage, right? Thanks. Again, not familiar with printk stuff,
glad you can help me go through this ;-)
Regards,
Boqun
> -ss
>
> > > > printk("\n *** DEADLOCK ***\n\n");
> > > > + } else if (cross_lock(src->instance)) {
> > > > + printk(" Possible unsafe locking scenario by
> > > > crosslock:\n\n");
> > > > + printk(" CPU0 CPU1\n");
> > > > + printk(" ---- ----\n");
> > > > + printk(" lock(");
> > > > + __print_lock_name(target);
> > > > + printk(KERN_CONT ");\n");
> > > > + printk(" lock(");
> > > > + __print_lock_name(source);
> > > > + printk(KERN_CONT ");\n");
> > > > + printk(" lock(");
> > > > + __print_lock_name(parent == source ? target : parent);
> > > > + printk(KERN_CONT ");\n");
> > > > + printk(" unlock(");
> > > > + __print_lock_name(source);
> > > > + printk(KERN_CONT ");\n");
> > > > + printk("\n *** DEADLOCK ***\n\n");
> > > > } else {
> > > > printk(" Possible unsafe locking scenario:\n\n");
> > > > printk(" CPU0 CPU1\n");
> > > > --
> > > > 2.14.1
> > > >
>
>
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