On Sat, 2006-08-12 at 17:28 +0200, Indan Zupancic wrote:

On Sat, August 12, 2006 17:06, Peter Zijlstra said:

quoted

On Sat, 2006-08-12 at 10:41 -0400, Jeff Garzik wrote:

quoted

Peter Zijlstra wrote:

quoted

Index: linux-2.6/include/linux/gfp.h
===================================================================

--- linux-2.6.orig/include/linux/gfp.h	2006-08-12 12:56:06.000000000 +0200
+++ linux-2.6/include/linux/gfp.h	2006-08-12 12:56:09.000000000 +0200

@@ -46,6 +46,7 @@ struct vm_area_struct;
 #define __GFP_ZERO	((__force gfp_t)0x8000u)/* Return zeroed page on success */
 #define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
 #define __GFP_HARDWALL   ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs

*/

quoted

+#define __GFP_MEMALLOC  ((__force gfp_t)0x40000u) /* Use emergency reserves */

This symbol name has nothing to do with its purpose.  The entire area of
code you are modifying could be described as having something to do with
'memalloc'.

GFP_EMERGENCY or GFP_USE_RESERVES or somesuch would be a far better
symbol name.

I recognize that is matches with GFP_NOMEMALLOC, but that doesn't change
the situation anyway.  In fact, a cleanup patch to rename GFP_NOMEMALLOC
would be nice.

I'm rather bad at picking names, but here goes:

PF_MEMALLOC      -> PF_EMERGALLOC
__GFP_NOMEMALLOC -> __GFP_NOEMERGALLOC
__GFP_MEMALLOC   -> __GFP_EMERGALLOC

    SOCK_MEMALLOC    -> SOCK_EMERGALLOC

quoted

Is that suitable and shall I prepare patches? Or do we want more ppl to
chime in and have a few more rounds?

Pardon my ignorance, but if we're doing cleanup anyway, why not use only one flag instead of two?
Why is __GFP_NOMEMALLOC needed when not setting __GFP_MEMALLOC could mean the same? Or else what
is the expected behaviour if both flags are set?

__GFP_NOMEMALLOC is most authorative; its use is (afaik) to negate
PF_MEMALLOC.

I agree that having both seems odd, but I haven't spend any significant
time on trying to find a 'nicer' solution.

--
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/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>