RE: can a kmalloc be both GFP_ATOMIC and GFP_KERNEL at the sametime?
From: Arjan van de Ven
Date: Sat Apr 28 2007 - 11:06:37 EST
> > i'd always assumed that the type flags of GFP_ATOMIC and GFP_KERNEL
> > were mutually exclusive when it came to calling kmalloc(), at least
> > based on everything i'd read. so i'm not sure how to interpret the
> > following:
> > drivers/scsi/aic7xxx_old.c: aic_dev = kmalloc(sizeof(struct aic_dev_data), GFP_ATOMIC | GFP_KERNEL);
> > drivers/message/i2o/device.c: resblk = kmalloc(buflen + 8, GFP_KERNEL | GFP_ATOMIC);
> > clarification?
> oh, i'm *aware* of the definitions of those flags, but every single
> source i've ever read has *strongly* suggested that you don't use
> those two flags together so i was surprised to see those combinations.
> (as an example, love's kernel book, p. 192, shows a table of valid
> combinations of flags to use, but doesn't mention the one above.)
> and, on the other hand, if they *are* legal to use together, i guess
> i'm kind of surprised that there would be only two instances of it.
it's not legal to use the combo; you have found yourself a very genuine
bug here! Good spotting!
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