diff options
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 49 |
1 files changed, 26 insertions, 23 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index cb181e437..85eaca9e5 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -108,17 +108,6 @@ static spinlock_t page_alloc_lock; * but this had better return false if any reasonable "get_free_page()" * allocation could currently fail.. * - * Currently we approve of the following situations: - * - the highest memory order has two entries - * - the highest memory order has one free entry and: - * - the next-highest memory order has two free entries - * - the highest memory order has one free entry and: - * - the next-highest memory order has one free entry - * - the next-next-highest memory order has two free entries - * - * [previously, there had to be two entries of the highest memory - * order, but this lead to problems on large-memory machines.] - * * This will return zero if no list was found, non-zero * if there was memory (the bigger, the better). */ @@ -126,7 +115,18 @@ int free_memory_available(int nr) { int retval = 0; unsigned long flags; - struct free_area_struct * list = NULL; + struct free_area_struct * list; + + /* + * If we have more than about 3% to 5% of all memory free, + * consider it to be good enough for anything. + * It may not be, due to fragmentation, but we + * don't want to keep on forever trying to find + * free unfragmented memory. + * Added low/high water marks to avoid thrashing -- Rik. + */ + if (nr_free_pages > (num_physpages >> 5) + (nr ? 0 : num_physpages >> 6)) + return nr+1; list = free_area + NR_MEM_LISTS; spin_lock_irqsave(&page_alloc_lock, flags); @@ -263,10 +263,8 @@ unsigned long __get_free_pages(int gfp_mask, unsigned long order) * "maxorder" is the highest order number that we're allowed * to empty in order to find a free page.. */ - maxorder = order + NR_MEM_LISTS/3; - if (gfp_mask & __GFP_MED) - maxorder += NR_MEM_LISTS/3; - if ((gfp_mask & __GFP_HIGH) || maxorder > NR_MEM_LISTS) + maxorder = NR_MEM_LISTS-1; + if (gfp_mask & __GFP_HIGH) maxorder = NR_MEM_LISTS; if (in_interrupt() && (gfp_mask & __GFP_WAIT)) { @@ -278,13 +276,18 @@ unsigned long __get_free_pages(int gfp_mask, unsigned long order) } } -repeat: - spin_lock_irqsave(&page_alloc_lock, flags); - RMQUEUE(order, maxorder, (gfp_mask & GFP_DMA)); - spin_unlock_irqrestore(&page_alloc_lock, flags); - if ((gfp_mask & __GFP_WAIT) && try_to_free_pages(gfp_mask,SWAP_CLUSTER_MAX)) - goto repeat; - + for (;;) { + spin_lock_irqsave(&page_alloc_lock, flags); + RMQUEUE(order, maxorder, (gfp_mask & GFP_DMA)); + spin_unlock_irqrestore(&page_alloc_lock, flags); + if (!(gfp_mask & __GFP_WAIT)) + break; + shrink_dcache(); + if (!try_to_free_pages(gfp_mask, SWAP_CLUSTER_MAX)) + break; + gfp_mask &= ~__GFP_WAIT; /* go through this only once */ + maxorder = NR_MEM_LISTS; /* Allow anything this time */ + } nopage: return 0; } |