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Commit eb5b5f02 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

x86: cpa, use page pool 



Switch the split page code to use the page pool. We do this
unconditionally to avoid different behaviour with and without
DEBUG_PAGEALLOC enabled.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 76ebd054

arch/x86/mm/pageattr.c

+25 −10
Original line number Diff line number Diff line
@@ -411,20 +411,29 @@ void __init cpa_init(void) 
static int split_large_page(pte_t *kpte, unsigned long address)

{

	unsigned long flags, pfn, pfninc = 1;

	gfp_t gfp_flags = GFP_KERNEL;

	unsigned int i, level;

	pte_t *pbase, *tmp;

	pgprot_t ref_prot;

	struct page *base;



#ifdef CONFIG_DEBUG_PAGEALLOC

	gfp_flags = GFP_ATOMIC | __GFP_NOWARN;

#endif

	base = alloc_pages(gfp_flags, 0);

	if (!base)

	/*

	 * Get a page from the pool. The pool list is protected by the

	 * pgd_lock, which we have to take anyway for the split

	 * operation:

	 */

	spin_lock_irqsave(&pgd_lock, flags);

	if (list_empty(&page_pool)) {

		spin_unlock_irqrestore(&pgd_lock, flags);

		return -ENOMEM;

	}



	base = list_first_entry(&page_pool, struct page, lru);

	list_del(&base->lru);

	pool_pages--;



	if (pool_pages < pool_low)

		pool_low = pool_pages;



	spin_lock_irqsave(&pgd_lock, flags);

	/*

	 * Check for races, another CPU might have split this page

	 * up for us already:
@@ -469,11 +478,17 @@ static int split_large_page(pte_t *kpte, unsigned long address) 
	base = NULL;



out_unlock:

	/*

	 * If we dropped out via the lookup_address check under

	 * pgd_lock then stick the page back into the pool:

	 */

	if (base) {

		list_add(&base->lru, &page_pool);

		pool_pages++;

	} else

		pool_used++;

	spin_unlock_irqrestore(&pgd_lock, flags);



	if (base)

		__free_pages(base, 0);



	return 0;

}