diff options
| -rw-r--r-- | arch/x86/mm/pageattr.c | 84 |
1 files changed, 51 insertions, 33 deletions
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 464d8fc21ce6..14e48b5a94ba 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -44,6 +44,12 @@ static inline unsigned long highmap_end_pfn(void) #endif +#ifdef CONFIG_DEBUG_PAGEALLOC +# define debug_pagealloc 1 +#else +# define debug_pagealloc 0 +#endif + static inline int within(unsigned long addr, unsigned long start, unsigned long end) { @@ -355,45 +361,48 @@ out_unlock: static LIST_HEAD(page_pool); static unsigned long pool_size, pool_pages, pool_low; -static unsigned long pool_used, pool_failed, pool_refill; +static unsigned long pool_used, pool_failed; -static void cpa_fill_pool(void) +static void cpa_fill_pool(struct page **ret) { - struct page *p; gfp_t gfp = GFP_KERNEL; + unsigned long flags; + struct page *p; - /* Do not allocate from interrupt context */ - if (in_irq() || irqs_disabled()) - return; /* - * Check unlocked. I does not matter when we have one more - * page in the pool. The bit lock avoids recursive pool - * allocations: + * Avoid recursion (on debug-pagealloc) and also signal + * our priority to get to these pagetables: */ - if (pool_pages >= pool_size || test_and_set_bit_lock(0, &pool_refill)) + if (current->flags & PF_MEMALLOC) return; + current->flags |= PF_MEMALLOC; -#ifdef CONFIG_DEBUG_PAGEALLOC /* - * We could do: - * gfp = in_atomic() ? GFP_ATOMIC : GFP_KERNEL; - * but this fails on !PREEMPT kernels + * Allocate atomically from atomic contexts: */ - gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN; -#endif + if (in_atomic() || irqs_disabled() || debug_pagealloc) + gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN; - while (pool_pages < pool_size) { + while (pool_pages < pool_size || (ret && !*ret)) { p = alloc_pages(gfp, 0); if (!p) { pool_failed++; break; } - spin_lock_irq(&pgd_lock); + /* + * If the call site needs a page right now, provide it: + */ + if (ret && !*ret) { + *ret = p; + continue; + } + spin_lock_irqsave(&pgd_lock, flags); list_add(&p->lru, &page_pool); pool_pages++; - spin_unlock_irq(&pgd_lock); + spin_unlock_irqrestore(&pgd_lock, flags); } - clear_bit_unlock(0, &pool_refill); + + current->flags &= ~PF_MEMALLOC; } #define SHIFT_MB (20 - PAGE_SHIFT) @@ -414,11 +423,15 @@ void __init cpa_init(void) * GiB. Shift MiB to Gib and multiply the result by * POOL_PAGES_PER_GB: */ - gb = ((si.totalram >> SHIFT_MB) + ROUND_MB_GB) >> SHIFT_MB_GB; - pool_size = POOL_PAGES_PER_GB * gb; + if (debug_pagealloc) { + gb = ((si.totalram >> SHIFT_MB) + ROUND_MB_GB) >> SHIFT_MB_GB; + pool_size = POOL_PAGES_PER_GB * gb; + } else { + pool_size = 1; + } pool_low = pool_size; - cpa_fill_pool(); + cpa_fill_pool(NULL); printk(KERN_DEBUG "CPA: page pool initialized %lu of %lu pages preallocated\n", pool_pages, pool_size); @@ -440,16 +453,20 @@ static int split_large_page(pte_t *kpte, unsigned long address) spin_lock_irqsave(&pgd_lock, flags); if (list_empty(&page_pool)) { spin_unlock_irqrestore(&pgd_lock, flags); - return -ENOMEM; + base = NULL; + cpa_fill_pool(&base); + if (!base) + return -ENOMEM; + spin_lock_irqsave(&pgd_lock, flags); + } else { + base = list_first_entry(&page_pool, struct page, lru); + list_del(&base->lru); + pool_pages--; + + if (pool_pages < pool_low) + pool_low = pool_pages; } - base = list_first_entry(&page_pool, struct page, lru); - list_del(&base->lru); - pool_pages--; - - if (pool_pages < pool_low) - pool_low = pool_pages; - /* * Check for races, another CPU might have split this page * up for us already: @@ -734,7 +751,8 @@ static int change_page_attr_set_clr(unsigned long addr, int numpages, cpa_flush_all(cache); out: - cpa_fill_pool(); + cpa_fill_pool(NULL); + return ret; } @@ -897,7 +915,7 @@ void kernel_map_pages(struct page *page, int numpages, int enable) * Try to refill the page pool here. We can do this only after * the tlb flush. */ - cpa_fill_pool(); + cpa_fill_pool(NULL); } #ifdef CONFIG_HIBERNATION |