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debugobjects: Export max loops counter

__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 ]

Yang Shi committed 8 years ago

Commit bd9dcd01 parent 7928b2c1 file · +8 −1Browse files

Showing the changes to lib/debugobjects.c (1 of 1 file). Show all

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lib/debugobjects.c+8−1
@@ -50,6 +50,7 @@ static int obj_pool_max_used; · 49 unmodified lines
50static struct kmem_cache *obj_cache;50static struct kmem_cache *obj_cache;
51 51
52static int debug_objects_maxchain __read_mostly;52static int debug_objects_maxchain __read_mostly;
53static int debug_objects_maxchecked __read_mostly;
53static int debug_objects_fixups __read_mostly;54static int debug_objects_fixups __read_mostly;
54static int debug_objects_warnings __read_mostly;55static int debug_objects_warnings __read_mostly;
55static int debug_objects_enabled __read_mostly56static 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 enum debug_obj_state state;721 enum debug_obj_state state;
721 struct debug_bucket *db;722 struct debug_bucket *db;
722 struct debug_obj *obj;723 struct debug_obj *obj;
723 int cnt;724 int cnt, objs_checked = 0;
724 725
725 saddr = (unsigned long) address;726 saddr = (unsigned long) address;
726 eaddr = saddr + size;727 eaddr = saddr + size;
@@ -765,7 +766,12 @@ repeat: · 38 unmodified lines
765 766
766 if (cnt > debug_objects_maxchain)767 if (cnt > debug_objects_maxchain)
767 debug_objects_maxchain = cnt;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
771void debug_check_no_obj_freed(const void *address, unsigned long size)777void 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
780static int debug_stats_show(struct seq_file *m, void *v)786static int debug_stats_show(struct seq_file *m, void *v)
781{787{
782 seq_printf(m, "max_chain :%d\n", debug_objects_maxchain);788 seq_printf(m, "max_chain :%d\n", debug_objects_maxchain);
789 seq_printf(m, "max_checked :%d\n", debug_objects_maxchecked);
783 seq_printf(m, "warnings :%d\n", debug_objects_warnings);790 seq_printf(m, "warnings :%d\n", debug_objects_warnings);
784 seq_printf(m, "fixups :%d\n", debug_objects_fixups);791 seq_printf(m, "fixups :%d\n", debug_objects_fixups);
785 seq_printf(m, "pool_free :%d\n", obj_pool_free);792 seq_printf(m, "pool_free :%d\n", obj_pool_free);