Thread (30 messages) 30 messages, 12 authors, 2011-06-12

Re: [PATCH] Make GFP_DMA allocations w/o ZONE_DMA emit a warning instead of failing

From: Dmitry Eremin-Solenikov <hidden>
Date: 2011-06-01 18:30:46
Also in: lkml

On 6/1/11, David Rientjes [off-list ref] wrote:
On Wed, 1 Jun 2011, Dmitry Eremin-Solenikov wrote:
quoted
I've hit this with IrDA driver on PXA. Also I've seen the report regarding
other ARM platform (ep-something). Thus I've included Russell in the cc.
So you want to continue to allow the page allocator to return pages from
anywhere, even when GFP_DMA is specified, just as though it was lowmem?
Yes and no. I'm asking for the grace period for the drivers authors to be able
to fix their code. After a grace period of one or two majors this permission
should be removed and your original patch should be effective.
Why don't you actually address the problem with the driver you're
complaining about with the patch below, which I already posted to you a
few days ago?

If this arm driver is going to be using GFP_DMA unconditionally, it better
require CONFIG_ZONE_DMA for it to actually be meaningful until such time
as it can be removed if it's truly not needed or generalized to only
specific pieces of hardware.
No. This only workarounds the bug. And also a possible hundred of other bugs
in the PXA/etc. ARM drivers. Instead I'm asking for the way to
visualize all such
bugs.

Do you want to also add such workarounds to some PATA CF driver used on PXA?
To _any_ of the drivers allocating the GFP_DMA memory? Then CONFIG_ZONE_DMA
would serve no purpose. We can as well to drop that symbol. Believe me.
quoted hunk ↗ jump to hunk
---
 drivers/net/irda/Kconfig |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/drivers/net/irda/Kconfig b/drivers/net/irda/Kconfig
--- a/drivers/net/irda/Kconfig
+++ b/drivers/net/irda/Kconfig
@@ -374,6 +374,7 @@ config VIA_FIR
 config PXA_FICP
 	tristate "Intel PXA2xx Internal FICP"
 	depends on ARCH_PXA && IRDA
+	select ZONE_DMA
 	help
 	  Say Y or M here if you want to build support for the PXA2xx
 	  built-in IRDA interface which can support both SIR and FIR.

-- 
With best wishes
Dmitry

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help