Commit 9023cb7e authored by Andy Whitcroft's avatar Andy Whitcroft Committed by Linus Torvalds
Browse files

slob: record page flag overlays explicitly 



SLOB reuses two page bits for internal purposes, it overlays PG_active and
PG_private.  This is hidden away in slob.c.  Document these overlays
explicitly in the main page-flags enum along with all the others.

Signed-off-by: default avatarAndy Whitcroft <apw@shadowen.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Reviewed-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8a38082d

include/linux/page-flags.h

+7 −0
Original line number Diff line number Diff line
@@ -105,6 +105,10 @@ enum pageflags { 
	PG_pinned = PG_owner_priv_1,

	PG_savepinned = PG_dirty,



	/* SLOB */

	PG_slob_page = PG_active,

	PG_slob_free = PG_private,



	/* SLUB */

	PG_slub_frozen = PG_active,

	PG_slub_debug = PG_error,
@@ -173,6 +177,9 @@ PAGEFLAG(Reserved, reserved) __CLEARPAGEFLAG(Reserved, reserved) 
PAGEFLAG(Private, private) __CLEARPAGEFLAG(Private, private)

	__SETPAGEFLAG(Private, private)



__PAGEFLAG(SlobPage, slob_page)

__PAGEFLAG(SlobFree, slob_free)



__PAGEFLAG(SlubFrozen, slub_frozen)

__PAGEFLAG(SlubDebug, slub_debug)

mm/slob.c

+6 −6
Original line number Diff line number Diff line
@@ -130,17 +130,17 @@ static LIST_HEAD(free_slob_large); 
 */

static inline int slob_page(struct slob_page *sp)

{

	return test_bit(PG_active, &sp->flags);

	return PageSlobPage((struct page *)sp);

}



static inline void set_slob_page(struct slob_page *sp)

{

	__set_bit(PG_active, &sp->flags);

	__SetPageSlobPage((struct page *)sp);

}



static inline void clear_slob_page(struct slob_page *sp)

{

	__clear_bit(PG_active, &sp->flags);

	__ClearPageSlobPage((struct page *)sp);

}



/*
@@ -148,19 +148,19 @@ static inline void clear_slob_page(struct slob_page *sp) 
 */

static inline int slob_page_free(struct slob_page *sp)

{

	return test_bit(PG_private, &sp->flags);

	return PageSlobFree((struct page *)sp);

}



static void set_slob_page_free(struct slob_page *sp, struct list_head *list)

{

	list_add(&sp->list, list);

	__set_bit(PG_private, &sp->flags);

	__SetPageSlobFree((struct page *)sp);

}



static inline void clear_slob_page_free(struct slob_page *sp)

{

	list_del(&sp->list);

	__clear_bit(PG_private, &sp->flags);

	__ClearPageSlobFree((struct page *)sp);

}



#define SLOB_UNIT sizeof(slob_t)

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