[PATCH] PG_uncached is ia64 only (f886ed44) · Commits · 戴 / test

As Nick points out, only ia64 uses PG_uncached. So we can push it up into the higher bits of the lower half of page->flags and make room for another flag on 32-bit machines. Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Jesse Barnes <jbarnes@sgi.com> Cc: Jes Sorensen <jes@trained-monkey.org> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Andy Whitcroft <apw@shadowen.org> Signed-off-by:

Andrew Morton <akpm@osdl.org> Signed-off-by:

Linus Torvalds <torvalds@osdl.org>

include/linux/page-flags.h

+13 −1

Original line number	Diff line number	Diff line
		@@ -7,6 +7,8 @@

		#include <linux/percpu.h>
		#include <linux/cache.h>
		#include <linux/types.h>

		#include <asm/pgtable.h>

		/*
		@@ -88,7 +90,17 @@
		#define PG_nosave_free 18 /* Free, should not be written */
		#define PG_buddy 19 /* Page is free, on buddy lists */

		#define PG_uncached 20 /* Page has been mapped as uncached */

		#if (BITS_PER_LONG > 32)
		/*
		* 64-bit-only flags build down from bit 31
		*
		* 32 bit -------------------------------\| FIELDS \| FLAGS \|
		* 64 bit \| FIELDS \| ?????? FLAGS \|
		* 63 32 0
		*/
		#define PG_uncached 31 /* Page has been mapped as uncached */
		#endif

		/*
		* Global page accounting. One instance per CPU. Only unsigned longs are

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