[PATCH CPA] [11/28] CPA: Change 32bit back to init_mm semaphore locking

Andi Kleen
2008-01-03T15:26:17Z

Now that debug pagealloc uses a separate function it is better
to change standard change_page_attr back to init_mm semaphore locking like 64bit.
Various things are simpler when sleeping is allowed.

Signed-off-by: Andi Kleen <ak@suse.de>

---
arch/x86/mm/pageattr_32.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)

Index: linux/arch/x86/mm/pageattr_32.c
===================================================================
--- linux.orig/arch/x86/mm/pageattr_32.c
+++ linux/arch/x86/mm/pageattr_32.c
@@ -14,10 +14,9 @@
#include <asm/pgalloc.h>
#include <asm/sections.h>

-static DEFINE_SPINLOCK(cpa_lock);
+/* Protected by init_mm.mmap_sem */
static struct list_head df_list = LIST_HEAD_INIT(df_list);

-
pte_t *lookup_address(unsigned long address, int *level)
{
pgd_t *pgd = pgd_offset_k(address);
@@ -46,9 +45,7 @@ static struct page *split_large_page(uns
struct page *base;
pte_t *pbase;

- spin_unlock_irq(&cpa_lock);
base = alloc_pages(GFP_KERNEL, 0);
- spin_lock_irq(&cpa_lock);
if (!base)
return NULL;

@@ -224,15 +221,14 @@ int change_page_attr(struct page *page,
{
int err = 0;
int i;
- unsigned long flags;

- spin_lock_irqsave(&cpa_lock, flags);
+ down_write(&init_mm.mmap_sem);
for (i = 0; i < numpages; i++, page++) {
err = __change_page_attr(page, prot);
if (err)
break;
}
- spin_unlock_irqrestore(&cpa_lock, flags);
+ up_write(&init_mm.mmap_sem);
return err;
}

@@ -243,9 +239,9 @@ void global_flush_tlb(void)

BUG_ON(irqs_disabled());

- spin_lock_irq(&cpa_lock);
+ down_write(&init_mm.mmap_sem);
list_replace_init(&df_list, &l);
- spin_unlock_irq(&cpa_lock);
+ up_write(&init_mm.mmap_sem);
flush_map(&l);
list_for_each_entry_safe(pg, next, &l, lru) {
list_del(&pg->lru);