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author | Nick Piggin <npiggin@suse.de> | 2006-03-22 00:08:08 -0800 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-22 07:53:58 -0800 |
commit | a482289d46587ffcda4c85aab109fb74910d7a48 (patch) | |
tree | 351dc5d9c09a4fe3d122c2157a298852ac8a821c /mm/hugetlb.c | |
parent | 545b1ea9bfa5a8ca9af33d63144bd4f2faaea8dd (diff) | |
download | kernel_samsung_smdk4412-a482289d46587ffcda4c85aab109fb74910d7a48.zip kernel_samsung_smdk4412-a482289d46587ffcda4c85aab109fb74910d7a48.tar.gz kernel_samsung_smdk4412-a482289d46587ffcda4c85aab109fb74910d7a48.tar.bz2 |
[PATCH] hugepage allocator cleanup
Insert "fresh" huge pages into the hugepage allocator by the same means as
they are freed back into it. This reduces code size and allows
enqueue_huge_page to be inlined into the hugepage free fastpath.
Eliminate occurances of hugepages on the free list with non-zero refcount.
This can allow stricter refcount checks in future. Also required for
lockless pagecache.
Signed-off-by: Nick Piggin <npiggin@suse.de>
"This patch also eliminates a leak "cleaned up" by re-clobbering the
refcount on every allocation from the hugepage freelists. With respect to
the lockless pagecache, the crucial aspect is to eliminate unconditional
set_page_count() to 0 on pages with potentially nonzero refcounts, though
closer inspection suggests the assignments removed are entirely spurious."
Acked-by: William Irwin <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm/hugetlb.c')
-rw-r--r-- | mm/hugetlb.c | 24 |
1 files changed, 8 insertions, 16 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 5087077..39d49ec 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -64,7 +64,7 @@ static struct page *dequeue_huge_page(struct vm_area_struct *vma, return page; } -static struct page *alloc_fresh_huge_page(void) +static int alloc_fresh_huge_page(void) { static int nid = 0; struct page *page; @@ -72,12 +72,15 @@ static struct page *alloc_fresh_huge_page(void) HUGETLB_PAGE_ORDER); nid = (nid + 1) % num_online_nodes(); if (page) { + page[1].lru.next = (void *)free_huge_page; /* dtor */ spin_lock(&hugetlb_lock); nr_huge_pages++; nr_huge_pages_node[page_to_nid(page)]++; spin_unlock(&hugetlb_lock); + put_page(page); /* free it into the hugepage allocator */ + return 1; } - return page; + return 0; } void free_huge_page(struct page *page) @@ -85,7 +88,6 @@ void free_huge_page(struct page *page) BUG_ON(page_count(page)); INIT_LIST_HEAD(&page->lru); - page[1].lru.next = NULL; /* reset dtor */ spin_lock(&hugetlb_lock); enqueue_huge_page(page); @@ -105,7 +107,6 @@ struct page *alloc_huge_page(struct vm_area_struct *vma, unsigned long addr) } spin_unlock(&hugetlb_lock); set_page_count(page, 1); - page[1].lru.next = (void *)free_huge_page; /* set dtor */ for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); ++i) clear_user_highpage(&page[i], addr); return page; @@ -114,7 +115,6 @@ struct page *alloc_huge_page(struct vm_area_struct *vma, unsigned long addr) static int __init hugetlb_init(void) { unsigned long i; - struct page *page; if (HPAGE_SHIFT == 0) return 0; @@ -123,12 +123,8 @@ static int __init hugetlb_init(void) INIT_LIST_HEAD(&hugepage_freelists[i]); for (i = 0; i < max_huge_pages; ++i) { - page = alloc_fresh_huge_page(); - if (!page) + if (!alloc_fresh_huge_page()) break; - spin_lock(&hugetlb_lock); - enqueue_huge_page(page); - spin_unlock(&hugetlb_lock); } max_huge_pages = free_huge_pages = nr_huge_pages = i; printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); @@ -154,8 +150,8 @@ static void update_and_free_page(struct page *page) page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | 1 << PG_private | 1<< PG_writeback); - set_page_count(&page[i], 0); } + page[1].lru.next = NULL; set_page_count(page, 1); __free_pages(page, HUGETLB_PAGE_ORDER); } @@ -188,12 +184,8 @@ static inline void try_to_free_low(unsigned long count) static unsigned long set_max_huge_pages(unsigned long count) { while (count > nr_huge_pages) { - struct page *page = alloc_fresh_huge_page(); - if (!page) + if (!alloc_fresh_huge_page()) return nr_huge_pages; - spin_lock(&hugetlb_lock); - enqueue_huge_page(page); - spin_unlock(&hugetlb_lock); } if (count >= nr_huge_pages) return nr_huge_pages; |