__debug_check_no_obj_freed() can be an expensive operation depending on the size of memory freed. It already exports the maximum chain walk length via debugfs, but this only records the maximum of a single memory chunk. Though there is no information about the total number of objects inspected for a __debug_check_no_obj_freed() operation, which might be significantly larger when a huge memory region is freed. Aggregate the number of objects inspected for a single invocation of __debug_check_no_obj_freed() and export it via sysfs. The resulting output of /sys/kernel/debug/debug_objects/stats looks like: max_chain :121 max_checked :543267 warnings :0 fixups :0 pool_free :1764 pool_min_free :341 pool_used :86438 pool_max_used :268887 objs_allocated:6068254 objs_freed :5981076 [ tglx: Renamed the variable to max_checked and adjusted changelog ]
Showing the changes to lib/debugobjects.c (1 of 1 file). Show all
Unified · Split
| @@ -50,6 +50,7 @@ static int obj_pool_max_used; · 49 unmodified lines | ||
| 50 | 50 | static struct kmem_cache *obj_cache; |
| 51 | 51 | |
| 52 | 52 | static int debug_objects_maxchain __read_mostly; |
| 53 | +static int debug_objects_maxchecked __read_mostly; | |
| 53 | 54 | static int debug_objects_fixups __read_mostly; |
| 54 | 55 | static int debug_objects_warnings __read_mostly; |
| 55 | 56 | static int debug_objects_enabled __read_mostly |
| @@ -720,7 +721,7 @@ static void __debug_check_no_obj_freed(const void *address, unsigned long size) · 664 unmodified lines | ||
| 720 | 721 | enum debug_obj_state state; |
| 721 | 722 | struct debug_bucket *db; |
| 722 | 723 | struct debug_obj *obj; |
| 723 | − int cnt; | |
| 724 | + int cnt, objs_checked = 0; | |
| 724 | 725 | |
| 725 | 726 | saddr = (unsigned long) address; |
| 726 | 727 | eaddr = saddr + size; |
| @@ -765,7 +766,12 @@ repeat: · 38 unmodified lines | ||
| 765 | 766 | |
| 766 | 767 | if (cnt > debug_objects_maxchain) |
| 767 | 768 | debug_objects_maxchain = cnt; |
| 769 | + | |
| 770 | + objs_checked += cnt; | |
| 768 | 771 | } |
| 772 | + | |
| 773 | + if (objs_checked > debug_objects_maxchecked) | |
| 774 | + debug_objects_maxchecked = objs_checked; | |
| 769 | 775 | } |
| 770 | 776 | |
| 771 | 777 | void debug_check_no_obj_freed(const void *address, unsigned long size) |
| @@ -780,6 +786,7 @@ void debug_check_no_obj_freed(const void *address, unsigned long size) · 8 unmodified lines | ||
| 780 | 786 | static int debug_stats_show(struct seq_file *m, void *v) |
| 781 | 787 | { |
| 782 | 788 | seq_printf(m, "max_chain :%d\n", debug_objects_maxchain); |
| 789 | + seq_printf(m, "max_checked :%d\n", debug_objects_maxchecked); | |
| 783 | 790 | seq_printf(m, "warnings :%d\n", debug_objects_warnings); |
| 784 | 791 | seq_printf(m, "fixups :%d\n", debug_objects_fixups); |
| 785 | 792 | seq_printf(m, "pool_free :%d\n", obj_pool_free); |