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authorYang Shi <yang.shi@linux.alibaba.com>2018-02-06 00:18:25 +0100
committerThomas Gleixner <tglx@linutronix.de>2018-02-13 10:58:58 +0100
commitbd9dcd046509cd5355605e43791eacee8bf5e40f (patch)
tree3b40437e4a2357eb74e321b4b11934bea31cc955 /lib
parentLinux 4.16-rc1 (diff)
downloadlinux-bd9dcd046509cd5355605e43791eacee8bf5e40f.tar.xz
linux-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')
-rw-r--r--lib/debugobjects.c9
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);