[PATCH 11/13] mm: fold sc.may_writepage and sc.may_swap into sc.flags

From: Wu Fengguang
Date: Tue Dec 06 2005 - 08:37:20 EST


Fold bool values into flags to make struct scan_control more compact.

Signed-off-by: Wu Fengguang <wfg@xxxxxxxxxxxxxxxx>
---

mm/vmscan.c | 22 ++++++++++------------
1 files changed, 10 insertions(+), 12 deletions(-)

--- linux-2.6.15-rc5-mm1.orig/mm/vmscan.c
+++ linux-2.6.15-rc5-mm1/mm/vmscan.c
@@ -72,12 +72,12 @@ struct scan_control {
/* This context's GFP mask */
gfp_t gfp_mask;

- int may_writepage;
-
- /* Can pages be swapped as part of reclaim? */
- int may_swap;
+ unsigned long flags;
};

+#define SC_MAY_WRITEPAGE 0x1
+#define SC_MAY_SWAP 0x2 /* Can pages be swapped as part of reclaim? */
+
#define lru_to_page(_head) (list_entry((_head)->prev, struct page, lru))

#ifdef ARCH_HAS_PREFETCH
@@ -483,7 +483,7 @@ static int shrink_list(struct list_head
* Try to allocate it some swap space here.
*/
if (PageAnon(page) && !PageSwapCache(page)) {
- if (!sc->may_swap)
+ if (!(sc->flags & SC_MAY_SWAP))
goto keep_locked;
if (!add_to_swap(page, GFP_ATOMIC))
goto activate_locked;
@@ -514,7 +514,7 @@ static int shrink_list(struct list_head
goto keep_locked;
if (!may_enter_fs)
goto keep_locked;
- if (laptop_mode && !sc->may_writepage)
+ if (laptop_mode && !(sc->flags & SC_MAY_WRITEPAGE))
goto keep_locked;

/* Page is dirty, try to write it out here */
@@ -1232,8 +1232,7 @@ int try_to_free_pages(struct zone **zone
delay_prefetch();

sc.gfp_mask = gfp_mask;
- sc.may_writepage = 0;
- sc.may_swap = 1;
+ sc.flags = SC_MAY_SWAP;
sc.nr_scanned = 0;
sc.nr_reclaimed = 0;

@@ -1276,7 +1275,7 @@ int try_to_free_pages(struct zone **zone
*/
if (sc.nr_scanned > SWAP_CLUSTER_MAX * 3 / 2) {
wakeup_pdflush(laptop_mode ? 0 : sc.nr_scanned);
- sc.may_writepage = 1;
+ sc.flags |= SC_MAY_WRITEPAGE;
}

/* Take a nap, wait for some writeback to complete */
@@ -1332,8 +1331,7 @@ static int balance_pgdat(pg_data_t *pgda

loop_again:
sc.gfp_mask = GFP_KERNEL;
- sc.may_writepage = 0;
- sc.may_swap = 1;
+ sc.flags = SC_MAY_SWAP;
sc.nr_mapped = read_page_state(nr_mapped);
sc.nr_scanned = 0;
sc.nr_reclaimed = 0;
@@ -1419,7 +1417,7 @@ scan_swspd:
*/
if (sc.nr_scanned > SWAP_CLUSTER_MAX * 2 &&
sc.nr_scanned > sc.nr_reclaimed + sc.nr_reclaimed / 2)
- sc.may_writepage = 1;
+ sc.flags |= SC_MAY_WRITEPAGE;

if (nr_pages && to_free > sc.nr_reclaimed)
continue; /* swsusp: need to do more work */

--
-
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