On 2019-10-06 00:44, Ming Lei wrote:
> +struct scsi_host_mq_in_flight {
> + int cnt;
> +};
Is this structure useful? Have you considered to use the 'int' datatype
directly and to leave out struct scsi_host_mq_in_flight?
> /**
> * scsi_host_busy - Return the host busy counter
> * @shost: Pointer to Scsi_Host to inc.
> **/
> int scsi_host_busy(struct Scsi_Host *shost)
> {
> - return atomic_read(&shost->host_busy);
> + struct scsi_host_mq_in_flight in_flight = {
> + .cnt = 0,
> + };
In case struct scsi_host_mq_in_flight would be retained, have you
considered to use "{ }" to initialize "in_flight"?
> -static void scsi_dec_host_busy(struct Scsi_Host *shost)
> +static void scsi_dec_host_busy(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
> {
> unsigned long flags;
>
> rcu_read_lock();
> - atomic_dec(&shost->host_busy);
> + clear_bit(SCMD_STATE_INFLIGHT, &cmd->state);
If a new state variable would be introduced for SCSI commands, would it
be possible to use non-atomic operations to set and clear
SCMD_STATE_INFLIGHT? In other words, are any of the functions that
modify this bit ever called concurrently?
Thanks,
Bart.
