* Wu Fengguang ([EMAIL PROTECTED]) wrote: > Add more comments to marker_synchronize_unregister() in order to > reduce the chance of misusing. > > Based on comments from Lai Jiangshan <[EMAIL PROTECTED]>. > > Cc: Lai Jiangshan <[EMAIL PROTECTED]> > Cc: Mathieu Desnoyers <[EMAIL PROTECTED]> > Signed-off-by: Wu Fengguang <[EMAIL PROTECTED]> > --- > > I'm still not sure about the last sentence. Can anyone clarify on > this? Thanks! > > diff --git a/include/linux/marker.h b/include/linux/marker.h > index 889196c..89ce1b8 100644 > --- a/include/linux/marker.h > +++ b/include/linux/marker.h > @@ -164,6 +164,12 @@ 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. > + * > + * It must be called _also_ between unregistration and destruction the data > + * that unregistration-ed probes need to make sure there is no caller > executing > + * a probe when it's data is destroyed.
it's -> its And the way it's written, this last sentence is a bit misleading. One might think that the synchronize_unregister has to be called two, when in fact it just has to be called once, but it must be called at a moment in time between unregister and free of any resource used by the probes, including the code which is removed by module unload. > + * > + * It works reliably only when all probe routines do not sleep and > reschedule. Per definition, preemption is disabled around marker probe execution, so I don't see why we should add this last sentence ? Mathieu > */ > #define marker_synchronize_unregister() synchronize_sched() > -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
