trace: module: Maintain a valid user count

commit 098507ae3ec2331476fb52e85d4040c1cc6d0ef4 upstream.

The replacement of the 'count' variable by two variables 'incs' and
'decs' to resolve some race conditions during module unloading was done
in parallel with some cleanup in the trace subsystem, and was integrated
as a merge.

Unfortunately, the formula for this replacement was wrong in the tracing
code, and the refcount in the traces was not usable as a result.

Use 'count = incs - decs' to compute the user count.

Link: http://lkml.kernel.org/p/1393924179-9147-1-git-send-email-romain.izard.pro@gmail.com

Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Fixes: c1ab9cab75 "merge conflict resolution"
Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Romain Izard 2014-03-04 10:09:39 +01:00 committed by Greg Kroah-Hartman
parent 863a921283
commit f6de6225ca

View file

@ -78,7 +78,7 @@ DECLARE_EVENT_CLASS(module_refcnt,
TP_fast_assign(
__entry->ip = ip;
__entry->refcnt = __this_cpu_read(mod->refptr->incs) + __this_cpu_read(mod->refptr->decs);
__entry->refcnt = __this_cpu_read(mod->refptr->incs) - __this_cpu_read(mod->refptr->decs);
__assign_str(name, mod->name);
),