The 31 bit limit for some of these cards is a problem, we currently only do __GFP_DMA for bounce buffer sg elements allocated for user supplied references in ioctls. I figure we should be using pci_alloc_consistent calls for these allocations to more accurately acquire memory within the 31 bit limit if necessary, we could switch to these to remove the need for the __GFP_DMA flag in the aacraid driver? -- Mark -----Original Message----- From: linux-scsi-owner@xxxxxxxxxxxxxxx [mailto:linux-scsi-owner@xxxxxxxxxxxxxxx] On Behalf Of James Bottomley Sent: Wednesday, May 23, 2007 11:18 AM To: Aubrey Li Cc: Christoph Lameter; Bernhard Walle; linux-scsi@xxxxxxxxxxxxxxx; Andrew Morton; linux-kernel@xxxxxxxxxxxxxxx Subject: Re: [PATCH] [scsi] Remove __GFP_DMA On Wed, 2007-05-23 at 10:41 +0800, Aubrey Li wrote: > On 5/23/07, Christoph Lameter <clameter@xxxxxxx> wrote: > > On Mon, 21 May 2007, Bernhard Walle wrote: > > > > > [PATCH] [scsi] Remove __GFP_DMA > > > > > > After 821de3a27bf33f11ec878562577c586cd5f83c64, it's not necessary to alloate a > > > DMA buffer any more in sd.c. > > > > > > Signed-off-by: Bernhard Walle <bwalle@xxxxxxx> > > > > Great that avoids a DMA kmalloc slab. Any other GFP_DMAs left in the scsi > > layer? > > > > Acked-by: Christoph Lameter <clameter@xxxxxxx> > > Yes, here is another patch I'll defer to Mark on this one. However, please remember that you can't just blindly remove GFP_DMA ... there are some cards which require it. Aacraid is one example ... it has a set of cards that can only DMA to 31 bits. For them, the GFP_DMA is necessary: The allocation in question is a scatterlist, which must be within the device DMA mask. James - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
