debugobjects: Export max loops counter (bd9dcd04) · Commits · 戴 / test

__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 ] Signed-off-by:

Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by:

Thomas Gleixner <tglx@linutronix.de> Cc: longman@redhat.com Link: https://lkml.kernel.org/r/1517872708-24207-2-git-send-email-yang.shi@linux.alibaba.com

lib/debugobjects.c

+8 −1

Original line number	Diff line number	Diff line
		@@ -50,6 +50,7 @@ static int obj_pool_max_used;
		static struct kmem_cache *obj_cache;

		static int debug_objects_maxchain __read_mostly;
		static int debug_objects_maxchecked __read_mostly;
		static int debug_objects_fixups __read_mostly;
		static int debug_objects_warnings __read_mostly;
		static int debug_objects_enabled __read_mostly
		@@ -720,7 +721,7 @@ static void __debug_check_no_obj_freed(const void *address, unsigned long size)
		enum debug_obj_state state;
		struct debug_bucket *db;
		struct debug_obj *obj;
		int cnt;
		int cnt, objs_checked = 0;

		saddr = (unsigned long) address;
		eaddr = saddr + size;
		@@ -765,7 +766,12 @@ repeat:

		if (cnt > debug_objects_maxchain)
		debug_objects_maxchain = cnt;

		objs_checked += cnt;
		}

		if (objs_checked > debug_objects_maxchecked)
		debug_objects_maxchecked = objs_checked;
		}

		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)
		static int debug_stats_show(struct seq_file m, void v)
		{
		seq_printf(m, "max_chain :%d\n", debug_objects_maxchain);
		seq_printf(m, "max_checked :%d\n", debug_objects_maxchecked);
		seq_printf(m, "warnings :%d\n", debug_objects_warnings);
		seq_printf(m, "fixups :%d\n", debug_objects_fixups);
		seq_printf(m, "pool_free :%d\n", obj_pool_free);

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