From 77311139f364d7f71fc9ba88f59fd90e60205007 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Mon, 31 Oct 2011 17:08:05 -0700 Subject: mm/debug-pagealloc.c: use plain __ratelimit() instead of printk_ratelimit() printk_ratelimit() should not be used, because it shares ratelimiting state with all other unrelated printk_ratelimit() callsites. Signed-off-by: Akinobu Mita Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/debug-pagealloc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'mm/debug-pagealloc.c') diff --git a/mm/debug-pagealloc.c b/mm/debug-pagealloc.c index a1e3324de2b..a4b6d707a31 100644 --- a/mm/debug-pagealloc.c +++ b/mm/debug-pagealloc.c @@ -2,6 +2,7 @@ #include #include #include +#include static inline void set_page_poison(struct page *page) { @@ -59,6 +60,7 @@ static bool single_bit_flip(unsigned char a, unsigned char b) static void check_poison_mem(unsigned char *mem, size_t bytes) { + static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 10); unsigned char *start; unsigned char *end; @@ -74,7 +76,7 @@ static void check_poison_mem(unsigned char *mem, size_t bytes) break; } - if (!printk_ratelimit()) + if (!__ratelimit(&ratelimit)) return; else if (start == end && single_bit_flip(*start, PAGE_POISON)) printk(KERN_ERR "pagealloc: single bit error\n"); -- cgit v1.2.3-70-g09d2 From 8c5fb8eadde41f67c61a7ac2d3246dab87bf7020 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Mon, 31 Oct 2011 17:08:10 -0700 Subject: mm/debug-pagealloc.c: use memchr_inv Use newly introduced memchr_inv() for page verification. Signed-off-by: Akinobu Mita Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/debug-pagealloc.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) (limited to 'mm/debug-pagealloc.c') diff --git a/mm/debug-pagealloc.c b/mm/debug-pagealloc.c index a4b6d707a31..2618933efdb 100644 --- a/mm/debug-pagealloc.c +++ b/mm/debug-pagealloc.c @@ -1,4 +1,5 @@ #include +#include #include #include #include @@ -64,11 +65,8 @@ static void check_poison_mem(unsigned char *mem, size_t bytes) unsigned char *start; unsigned char *end; - for (start = mem; start < mem + bytes; start++) { - if (*start != PAGE_POISON) - break; - } - if (start == mem + bytes) + start = memchr_inv(mem, PAGE_POISON, bytes); + if (!start) return; for (end = mem + bytes - 1; end > start; end--) { -- cgit v1.2.3-70-g09d2 From 64212ec569bfdd094f7a23d9b09862209a983559 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Mon, 31 Oct 2011 17:08:38 -0700 Subject: debug-pagealloc: add support for highmem pages This adds support for highmem pages poisoning and verification to the debug-pagealloc feature for no-architecture support. [akpm@linux-foundation.org: remove unneeded preempt_disable/enable] Signed-off-by: Akinobu Mita Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/debug-pagealloc.c | 44 ++++++++++---------------------------------- 1 file changed, 10 insertions(+), 34 deletions(-) (limited to 'mm/debug-pagealloc.c') diff --git a/mm/debug-pagealloc.c b/mm/debug-pagealloc.c index 2618933efdb..7cea557407f 100644 --- a/mm/debug-pagealloc.c +++ b/mm/debug-pagealloc.c @@ -1,6 +1,7 @@ #include #include #include +#include #include #include #include @@ -20,28 +21,13 @@ static inline bool page_poison(struct page *page) return test_bit(PAGE_DEBUG_FLAG_POISON, &page->debug_flags); } -static void poison_highpage(struct page *page) -{ - /* - * Page poisoning for highmem pages is not implemented. - * - * This can be called from interrupt contexts. - * So we need to create a new kmap_atomic slot for this - * application and it will need interrupt protection. - */ -} - static void poison_page(struct page *page) { - void *addr; + void *addr = kmap_atomic(page); - if (PageHighMem(page)) { - poison_highpage(page); - return; - } set_page_poison(page); - addr = page_address(page); memset(addr, PAGE_POISON, PAGE_SIZE); + kunmap_atomic(addr); } static void poison_pages(struct page *page, int n) @@ -86,27 +72,17 @@ static void check_poison_mem(unsigned char *mem, size_t bytes) dump_stack(); } -static void unpoison_highpage(struct page *page) -{ - /* - * See comment in poison_highpage(). - * Highmem pages should not be poisoned for now - */ - BUG_ON(page_poison(page)); -} - static void unpoison_page(struct page *page) { - if (PageHighMem(page)) { - unpoison_highpage(page); + void *addr; + + if (!page_poison(page)) return; - } - if (page_poison(page)) { - void *addr = page_address(page); - check_poison_mem(addr, PAGE_SIZE); - clear_page_poison(page); - } + addr = kmap_atomic(page); + check_poison_mem(addr, PAGE_SIZE); + clear_page_poison(page); + kunmap_atomic(addr); } static void unpoison_pages(struct page *page, int n) -- cgit v1.2.3-70-g09d2