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Commit 224abf92 authored by Nick Piggin's avatar Nick Piggin Committed by Linus Torvalds
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[PATCH] mm: bad_page optimisation 



Cut down size slightly by not passing bad_page the function name (it should be
able to be determined by dump_stack()).  And cut down the number of printks in
bad_page.

Also, cut down some branching in the destroy_compound_page path.

Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 9328b8fa

mm/page_alloc.c

+20 −24
Original line number Diff line number Diff line
@@ -132,16 +132,16 @@ static inline int bad_range(struct zone *zone, struct page *page) 
}

#endif



static void bad_page(const char *function, struct page *page)

{

	printk(KERN_EMERG "Bad page state at %s (in process '%s', page %p)\n",

		function, current->comm, page);

	printk(KERN_EMERG "flags:0x%0*lx mapping:%p mapcount:%d count:%d\n",

		(int)(2*sizeof(unsigned long)), (unsigned long)page->flags,

		page->mapping, page_mapcount(page), page_count(page));

	printk(KERN_EMERG "Backtrace:\n");

static void bad_page(struct page *page)

{

	printk(KERN_EMERG "Bad page state in process '%s'\n"

		"page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n"

		"Trying to fix it up, but a reboot is needed\n"

		"Backtrace:\n",

		current->comm, page, (int)(2*sizeof(unsigned long)),

		(unsigned long)page->flags, page->mapping,

		page_mapcount(page), page_count(page));

	dump_stack();

	printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n");

	page->flags &= ~(1 << PG_lru	|

			1 << PG_private |

			1 << PG_locked	|
@@ -194,19 +194,15 @@ static void destroy_compound_page(struct page *page, unsigned long order) 
	int i;

	int nr_pages = 1 << order;



	if (!PageCompound(page))

		return;



	if (page[1].index != order)

		bad_page(__FUNCTION__, page);

	if (unlikely(page[1].index != order))

		bad_page(page);



	for (i = 0; i < nr_pages; i++) {

		struct page *p = page + i;



		if (!PageCompound(p))

			bad_page(__FUNCTION__, page);

		if (page_private(p) != (unsigned long)page)

			bad_page(__FUNCTION__, page);

		if (unlikely(!PageCompound(p) |

				(page_private(p) != (unsigned long)page)))

			bad_page(page);

		ClearPageCompound(p);

	}

}
@@ -316,7 +312,7 @@ static inline void __free_pages_bulk (struct page *page, 
	unsigned long page_idx;

	int order_size = 1 << order;



	if (unlikely(order))

	if (unlikely(PageCompound(page)))

		destroy_compound_page(page, order);



	page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
@@ -348,7 +344,7 @@ static inline void __free_pages_bulk (struct page *page, 
	zone->free_area[order].nr_free++;

}



static inline int free_pages_check(const char *function, struct page *page)

static inline int free_pages_check(struct page *page)

{

	if (unlikely(page_mapcount(page) |

		(page->mapping != NULL)  |
@@ -363,7 +359,7 @@ static inline int free_pages_check(const char *function, struct page *page) 
			1 << PG_swapcache |

			1 << PG_writeback |

			1 << PG_reserved ))))

		bad_page(function, page);

		bad_page(page);

	if (PageDirty(page))

		__ClearPageDirty(page);

	/*
@@ -422,7 +418,7 @@ void __free_pages_ok(struct page *page, unsigned int order) 
#endif



	for (i = 0 ; i < (1 << order) ; ++i)

		reserved += free_pages_check(__FUNCTION__, page + i);

		reserved += free_pages_check(page + i);

	if (reserved)

		return;
@@ -517,7 +513,7 @@ static int prep_new_page(struct page *page, int order) 
			1 << PG_swapcache |

			1 << PG_writeback |

			1 << PG_reserved ))))

		bad_page(__FUNCTION__, page);

		bad_page(page);



	/*

	 * For now, we report if PG_reserved was found set, but do not
@@ -716,7 +712,7 @@ static void fastcall free_hot_cold_page(struct page *page, int cold) 


	if (PageAnon(page))

		page->mapping = NULL;

	if (free_pages_check(__FUNCTION__, page))

	if (free_pages_check(page))

		return;



	inc_page_state(pgfree);