Commit-ID: bd9dcd046509cd5355605e43791eacee8bf5e40f Gitweb: https://git.kernel.org/tip/bd9dcd046509cd5355605e43791eacee8bf5e40f Author: Yang Shi <yang....@linux.alibaba.com> AuthorDate: Tue, 6 Feb 2018 07:18:25 +0800 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Tue, 13 Feb 2018 10:58:58 +0100
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 ] Signed-off-by: Yang Shi <yang....@linux.alibaba.com> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Cc: long...@redhat.com Link: https://lkml.kernel.org/r/1517872708-24207-2-git-send-email-yang....@linux.alibaba.com --- lib/debugobjects.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/lib/debugobjects.c b/lib/debugobjects.c index 2f5349c..f6d57a1 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -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);
