From 4b8a96744c0c27ab94fb4e8155d4384c3b399e27 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Tue, 7 Jul 2009 10:32:56 +0100 Subject: kmemleak: Add more cond_resched() calls in the scanning thread Following recent fix to no longer reschedule in the scan_block() function, the system may become unresponsive with !PREEMPT. This patch re-adds the cond_resched() call to scan_block() but conditioned by the allow_resched parameter. Signed-off-by: Catalin Marinas Cc: Ingo Molnar --- mm/kmemleak.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 6006553..93f1481 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -807,7 +807,7 @@ static int scan_should_stop(void) * found to the gray list. */ static void scan_block(void *_start, void *_end, - struct kmemleak_object *scanned) + struct kmemleak_object *scanned, int allow_resched) { unsigned long *ptr; unsigned long *start = PTR_ALIGN(_start, BYTES_PER_POINTER); @@ -818,6 +818,8 @@ static void scan_block(void *_start, void *_end, unsigned long pointer = *ptr; struct kmemleak_object *object; + if (allow_resched) + cond_resched(); if (scan_should_stop()) break; @@ -881,12 +883,12 @@ static void scan_object(struct kmemleak_object *object) goto out; if (hlist_empty(&object->area_list)) scan_block((void *)object->pointer, - (void *)(object->pointer + object->size), object); + (void *)(object->pointer + object->size), object, 0); else hlist_for_each_entry(area, elem, &object->area_list, node) scan_block((void *)(object->pointer + area->offset), (void *)(object->pointer + area->offset - + area->length), object); + + area->length), object, 0); out: spin_unlock_irqrestore(&object->lock, flags); } @@ -931,14 +933,14 @@ static void kmemleak_scan(void) rcu_read_unlock(); /* data/bss scanning */ - scan_block(_sdata, _edata, NULL); - scan_block(__bss_start, __bss_stop, NULL); + scan_block(_sdata, _edata, NULL, 1); + scan_block(__bss_start, __bss_stop, NULL, 1); #ifdef CONFIG_SMP /* per-cpu sections scanning */ for_each_possible_cpu(i) scan_block(__per_cpu_start + per_cpu_offset(i), - __per_cpu_end + per_cpu_offset(i), NULL); + __per_cpu_end + per_cpu_offset(i), NULL, 1); #endif /* @@ -960,7 +962,7 @@ static void kmemleak_scan(void) /* only scan if page is in use */ if (page_count(page) == 0) continue; - scan_block(page, page + 1, NULL); + scan_block(page, page + 1, NULL, 1); } } @@ -972,7 +974,8 @@ static void kmemleak_scan(void) read_lock(&tasklist_lock); for_each_process(task) scan_block(task_stack_page(task), - task_stack_page(task) + THREAD_SIZE, NULL); + task_stack_page(task) + THREAD_SIZE, + NULL, 0); read_unlock(&tasklist_lock); } -- cgit v1.1