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| author | Yang Shi <yang.shi@linux.alibaba.com> | 2018-02-06 07:18:25 +0800 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-02-13 10:58:58 +0100 |
| commit | bd9dcd046509cd5355605e43791eacee8bf5e40f (patch) | |
| tree | 3b40437e4a2357eb74e321b4b11934bea31cc955 /lib/debugobjects.c | |
| parent | 7928b2cbe55b2a410a0f5c1f154610059c57b1b2 (diff) | |
| download | lwn-bd9dcd046509cd5355605e43791eacee8bf5e40f.tar.gz lwn-bd9dcd046509cd5355605e43791eacee8bf5e40f.zip | |
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.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
Diffstat (limited to 'lib/debugobjects.c')
| -rw-r--r-- | lib/debugobjects.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/lib/debugobjects.c b/lib/debugobjects.c index 2f5349c6e81a..f6d57a11c927 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); |