markers: comment marker_synchronize_unregister() on data dependency

Add document and comments on marker_synchronize_unregister(): it
should be called before freeing resources that the probes depend on.

Based on comments from Lai Jiangshan and Mathieu Desnoyers.

Signed-off-by: Wu Fengguang <wfg@linux.intel.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Wu Fengguang
2008-11-27 16:14:44 +08:00
committed by Ingo Molnar
parent c7cc773076
commit a838c2ec6e
2 changed files with 14 additions and 7 deletions

View File

@@ -211,8 +211,10 @@ extern void *marker_get_private_data(const char *name, marker_probe_func *probe,
/*
* marker_synchronize_unregister must be called between the last marker probe
* unregistration and the end of module exit to make sure there is no caller
* executing a probe when it is freed.
* unregistration and the first one of
* - the end of module exit function
* - the free of any resource used by the probes
* to ensure the code and data are valid for any possibly running probes.
*/
#define marker_synchronize_unregister() synchronize_sched()