On 18/12/2014 04:15, Wu, Feng wrote: > Thanks for your comments, Paolo! > > If we use u64 new_control, we cannot use new.sn any more. > Maybe we can change the struct pi_desc {} like this: > > typedef struct pid_control{ > u64 on : 1, > sn : 1, > rsvd_1 : 13, > ndm : 1, > nv : 8, > rsvd_2 : 8, > ndst : 32; > }pid_control_t; > > struct pi_desc { > u32 pir[8]; /* Posted interrupt requested */ > pid_control_t control; Probably something like this to keep the union: typedef union pid_control { u64 full; struct { u64 on : 1, ... } fields; }; > u32 rsvd[6]; > } __aligned(64); > > > Then we can define pid_control_t new_control, old_control. And use new_control.sn = 0. > > What is your opinon? Sure. Alternatively, keep using struct pi_desc new; just do not zero it, nor access any field outide the control word. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html