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authorMartin Schwidefsky2013-02-28 11:08:54 +0100
committerMartin Schwidefsky2013-04-17 14:07:24 +0200
commit7919e91b34316ee30b14334389e005eb2e9b8e39 (patch)
tree8a4e0583cd0ef46d27e4725c58ece70f3253a3ad /arch/s390/mm
parentf752ac4d7d96159776b0eea47489796bd90856fd (diff)
s390/mm: zero page cache synonyms for zEC12
To avoid cache synonyms on System zEC12 32 independent zero pages are required, one for each combination for bits 2**12 to 2**16 of the virtual address. To avoid wasting too much memory on small virtual systems the number of zero pages is limited to 4 if the memory size is less or equal to 64MB. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/mm')
-rw-r--r--arch/s390/mm/init.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 49ce6bb2c641..9f9c315b4c07 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -63,10 +63,18 @@ static unsigned long __init setup_zero_pages(void)
break;
case 0x2097: /* z10 */
case 0x2098: /* z10 */
- default:
+ case 0x2817: /* z196 */
+ case 0x2818: /* z196 */
order = 2;
break;
+ case 0x2827: /* zEC12 */
+ default:
+ order = 5;
+ break;
}
+ /* Limit number of empty zero pages for small memory sizes */
+ if (order > 2 && totalram_pages <= 16384)
+ order = 2;
empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
if (!empty_zero_page)