Re: [PATCH] mm: Warn about costly page allocation

From: Minchan Kim
Date: Mon Jul 09 2012 - 10:12:32 EST


Hi Cong,

On Mon, Jul 09, 2012 at 12:53:22PM +0000, Cong Wang wrote:
> On Mon, 09 Jul 2012 at 08:46 GMT, Minchan Kim <minchan@xxxxxxxxxx> wrote:
> >>
> >> WARN_ON_ONCE would tell you what is trying to satisfy the allocation.
> >
> > Do you mean that it would be better to use WARN_ON_ONCE rather than raw printk?
> > If so, I would like to insist raw printk because WARN_ON_ONCE could be disabled
> > by !CONFIG_BUG.
> > If I miss something, could you elaborate it more?
> >
>
> Raw printk could be disabled by !CONFIG_PRINTK too, and given that:

Yes.
In such case, It is very hard to diagnose the system so at least
we enables CONFIG_PRINTK.

>
> config PRINTK
> default y
> bool "Enable support for printk" if EXPERT
>
> config BUG
> bool "BUG() support" if EXPERT
> default y
>
> they are both configurable only when ERPERT, so we don't need to
> worry much. :)

Embedded can use CONFIG_PRINTK and !CONFIG_BUG for size optimization
and printk(pr_xxx) + dump_stack is common technic used in all over kernel
sources. Do you have any reason you don't like it?


>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/