From 6e9ed0cc4b963fde66ab47d9fb19147631e44555 Mon Sep 17 00:00:00 2001 From: Américo Wang Date: Mon, 19 Jan 2009 02:00:38 +0800 Subject: slob: clean up the code - Use NULL instead of plain 0; - Rename slob_page() to is_slob_page(); - Define slob_page() to convert void* to struct slob_page*; - Rename slob_new_page() to slob_new_pages(); - Define slob_free_pages() accordingly. Compile tests only. Signed-off-by: WANG Cong Signed-off-by: Matt Mackall Cc: Christoph Lameter Signed-off-by: Pekka Enberg --- mm/slob.c | 40 +++++++++++++++++++++++++--------------- 1 file changed, 25 insertions(+), 15 deletions(-) (limited to 'mm/slob.c') diff --git a/mm/slob.c b/mm/slob.c index bf7e8fc3aed8..c9cd31d27e69 100644 --- a/mm/slob.c +++ b/mm/slob.c @@ -126,9 +126,9 @@ static LIST_HEAD(free_slob_medium); static LIST_HEAD(free_slob_large); /* - * slob_page: True for all slob pages (false for bigblock pages) + * is_slob_page: True for all slob pages (false for bigblock pages) */ -static inline int slob_page(struct slob_page *sp) +static inline int is_slob_page(struct slob_page *sp) { return PageSlobPage((struct page *)sp); } @@ -143,6 +143,11 @@ static inline void clear_slob_page(struct slob_page *sp) __ClearPageSlobPage((struct page *)sp); } +static inline struct slob_page *slob_page(const void *addr) +{ + return (struct slob_page *)virt_to_page(addr); +} + /* * slob_page_free: true for pages on free_slob_pages list. */ @@ -230,7 +235,7 @@ static int slob_last(slob_t *s) return !((unsigned long)slob_next(s) & ~PAGE_MASK); } -static void *slob_new_page(gfp_t gfp, int order, int node) +static void *slob_new_pages(gfp_t gfp, int order, int node) { void *page; @@ -247,12 +252,17 @@ static void *slob_new_page(gfp_t gfp, int order, int node) return page_address(page); } +static void slob_free_pages(void *b, int order) +{ + free_pages((unsigned long)b, order); +} + /* * Allocate a slob block within a given slob_page sp. */ static void *slob_page_alloc(struct slob_page *sp, size_t size, int align) { - slob_t *prev, *cur, *aligned = 0; + slob_t *prev, *cur, *aligned = NULL; int delta = 0, units = SLOB_UNITS(size); for (prev = NULL, cur = sp->free; ; prev = cur, cur = slob_next(cur)) { @@ -349,10 +359,10 @@ static void *slob_alloc(size_t size, gfp_t gfp, int align, int node) /* Not enough space: must allocate a new page */ if (!b) { - b = slob_new_page(gfp & ~__GFP_ZERO, 0, node); + b = slob_new_pages(gfp & ~__GFP_ZERO, 0, node); if (!b) - return 0; - sp = (struct slob_page *)virt_to_page(b); + return NULL; + sp = slob_page(b); set_slob_page(sp); spin_lock_irqsave(&slob_lock, flags); @@ -384,7 +394,7 @@ static void slob_free(void *block, int size) return; BUG_ON(!size); - sp = (struct slob_page *)virt_to_page(block); + sp = slob_page(block); units = SLOB_UNITS(size); spin_lock_irqsave(&slob_lock, flags); @@ -476,7 +486,7 @@ void *__kmalloc_node(size_t size, gfp_t gfp, int node) } else { void *ret; - ret = slob_new_page(gfp | __GFP_COMP, get_order(size), node); + ret = slob_new_pages(gfp | __GFP_COMP, get_order(size), node); if (ret) { struct page *page; page = virt_to_page(ret); @@ -494,8 +504,8 @@ void kfree(const void *block) if (unlikely(ZERO_OR_NULL_PTR(block))) return; - sp = (struct slob_page *)virt_to_page(block); - if (slob_page(sp)) { + sp = slob_page(block); + if (is_slob_page(sp)) { int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN); unsigned int *m = (unsigned int *)(block - align); slob_free(m, *m + align); @@ -513,8 +523,8 @@ size_t ksize(const void *block) if (unlikely(block == ZERO_SIZE_PTR)) return 0; - sp = (struct slob_page *)virt_to_page(block); - if (slob_page(sp)) { + sp = slob_page(block); + if (is_slob_page(sp)) { int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN); unsigned int *m = (unsigned int *)(block - align); return SLOB_UNITS(*m) * SLOB_UNIT; @@ -572,7 +582,7 @@ void *kmem_cache_alloc_node(struct kmem_cache *c, gfp_t flags, int node) if (c->size < PAGE_SIZE) b = slob_alloc(c->size, flags, c->align, node); else - b = slob_new_page(flags, get_order(c->size), node); + b = slob_new_pages(flags, get_order(c->size), node); if (c->ctor) c->ctor(b); @@ -586,7 +596,7 @@ static void __kmem_cache_free(void *b, int size) if (size < PAGE_SIZE) slob_free(b, size); else - free_pages((unsigned long)b, get_order(size)); + slob_free_pages(b, get_order(size)); } static void kmem_rcu_free(struct rcu_head *head) -- cgit v1.2.3-59-g8ed1b From 6fb8f424393025674fde7869b59f485d1e352182 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Mon, 16 Mar 2009 21:00:28 +1100 Subject: slob: fix lockup in slob_free() Don't hold SLOB lock when freeing the page. Reduces lock hold width. See the following thread for discussion of the bug: http://marc.info/?l=linux-kernel&m=123709983214143&w=2 Reported-by: Ingo Molnar Acked-by: Matt Mackall Signed-off-by: Nick Piggin Signed-off-by: Pekka Enberg --- mm/slob.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'mm/slob.c') diff --git a/mm/slob.c b/mm/slob.c index bf7e8fc3aed8..f901653707a4 100644 --- a/mm/slob.c +++ b/mm/slob.c @@ -393,10 +393,11 @@ static void slob_free(void *block, int size) /* Go directly to page allocator. Do not pass slob allocator */ if (slob_page_free(sp)) clear_slob_page_free(sp); + spin_unlock_irqrestore(&slob_lock, flags); clear_slob_page(sp); free_slob_page(sp); free_page((unsigned long)b); - goto out; + return; } if (!slob_page_free(sp)) { -- cgit v1.2.3-59-g8ed1b