RE: SLAB_LEVEL_MASK question

Henry Qian
2003-09-04T20:19:42Z

The other flags are __GFP_WAIT, __GFP_HIGH, __GFP_IO, __GFP_HIGHIO, and
__GFP_FS (flags == 0x1f0).

So this must be something else's wrong. I was using madwifi Atheros
driver.

Thank you very much,

Henry

-----Original Message-----
From: Manfred Spraul [mailto:manfred@colorfullife.com]
Sent: Thursday, September 04, 2003 3:50 PM
To: Henry Qian
Cc: linux-kernel@vger.kernel.org
Subject: Re: SLAB_LEVEL_MASK question

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