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		96990a4ae9
		
	
	
	
	
		
			
			Quicklists calculates the size of the quicklists based on the number of free pages. This must be the number of free pages that can be allocated with GFP_KERNEL. node_page_state() includes the pages in ZONE_HIGHMEM and ZONE_MOVABLE which may lead the quicklists to become too large causing OOM. Signed-off-by: Christoph Lameter <clameter@sgi.com> Tested-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
			
				
	
	
		
			97 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			97 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Quicklist support.
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|  *
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|  * Quicklists are light weight lists of pages that have a defined state
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|  * on alloc and free. Pages must be in the quicklist specific defined state
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|  * (zero by default) when the page is freed. It seems that the initial idea
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|  * for such lists first came from Dave Miller and then various other people
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|  * improved on it.
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|  *
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|  * Copyright (C) 2007 SGI,
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|  * 	Christoph Lameter <clameter@sgi.com>
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|  * 		Generalized, added support for multiple lists and
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|  * 		constructors / destructors.
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|  */
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| #include <linux/kernel.h>
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| 
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| #include <linux/mm.h>
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| #include <linux/mmzone.h>
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| #include <linux/module.h>
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| #include <linux/quicklist.h>
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| 
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| DEFINE_PER_CPU(struct quicklist, quicklist)[CONFIG_NR_QUICK];
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| 
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| #define FRACTION_OF_NODE_MEM	16
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| 
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| static unsigned long max_pages(unsigned long min_pages)
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| {
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| 	unsigned long node_free_pages, max;
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| 	struct zone *zones = NODE_DATA(numa_node_id())->node_zones;
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| 
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| 	node_free_pages =
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| #ifdef CONFIG_ZONE_DMA
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| 		zone_page_state(&zones[ZONE_DMA], NR_FREE_PAGES) +
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| #endif
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| #ifdef CONFIG_ZONE_DMA32
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| 		zone_page_state(&zones[ZONE_DMA32], NR_FREE_PAGES) +
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| #endif
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| 		zone_page_state(&zones[ZONE_NORMAL], NR_FREE_PAGES);
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| 
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| 	max = node_free_pages / FRACTION_OF_NODE_MEM;
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| 	return max(max, min_pages);
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| }
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| 
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| static long min_pages_to_free(struct quicklist *q,
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| 	unsigned long min_pages, long max_free)
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| {
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| 	long pages_to_free;
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| 
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| 	pages_to_free = q->nr_pages - max_pages(min_pages);
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| 
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| 	return min(pages_to_free, max_free);
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| }
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| 
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| /*
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|  * Trim down the number of pages in the quicklist
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|  */
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| void quicklist_trim(int nr, void (*dtor)(void *),
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| 	unsigned long min_pages, unsigned long max_free)
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| {
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| 	long pages_to_free;
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| 	struct quicklist *q;
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| 
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| 	q = &get_cpu_var(quicklist)[nr];
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| 	if (q->nr_pages > min_pages) {
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| 		pages_to_free = min_pages_to_free(q, min_pages, max_free);
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| 
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| 		while (pages_to_free > 0) {
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| 			/*
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| 			 * We pass a gfp_t of 0 to quicklist_alloc here
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| 			 * because we will never call into the page allocator.
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| 			 */
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| 			void *p = quicklist_alloc(nr, 0, NULL);
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| 
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| 			if (dtor)
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| 				dtor(p);
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| 			free_page((unsigned long)p);
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| 			pages_to_free--;
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| 		}
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| 	}
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| 	put_cpu_var(quicklist);
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| }
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| 
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| unsigned long quicklist_total_size(void)
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| {
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| 	unsigned long count = 0;
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| 	int cpu;
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| 	struct quicklist *ql, *q;
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| 
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| 	for_each_online_cpu(cpu) {
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| 		ql = per_cpu(quicklist, cpu);
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| 		for (q = ql; q < ql + CONFIG_NR_QUICK; q++)
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| 			count += q->nr_pages;
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| 	}
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| 	return count;
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| }
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| 
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