Re: SLAB_LEVEL_MASK question

Manfred Spraul
2003-09-04T19:50:11Z

Hi Henry,

>The kernel panics because in the flags variable, I have other flags
>(0x1f0) besides SLAB_ATOMIC.
>
>
Which flags were set? __GFP_WAIT must not be set [i.e. will panic], the
other combinations are invalid. The only legal values for the flags
variable are 0 or SLAB_ATOMIC [aka GFP_ATOMIC, aka __GFP_HIGH].

>I modified it to:
>
> if (in_interrupt() && (flags & SLAB_ATOMIC) != SLAB_ATOMIC)
> BUG();
>
>It seems working fine.
>
>Is this good?
>
>
No, it's wrong. Your driver will panic once in a while, especially under
memory intensive stress tests.

--
Manfred