Re: 答复: Re: 答复: Re: [PATCH v2] scsi: Introduce sdev_printk_ratelimited tothrottlefrequent printk
On Mon 2018-04-09 10:13:43, wen.yan...@zte.com.cn wrote: > That's a good idea, but it only solves part of the problem. > loopping printks under spinlock, there's two path: > one path is: > scsi_request_fn --> loop -> blk_peek_request-> scsi_prep_fn -> > scsi_prep_state_check -> sdev_printk > another path is: > scsi_request_fn --> loop -> sdev_printk Is this message redundant? It seems to be printed in the same situations as the messages in scsi_prep_state_check(). In fact, there seems to be a mismatch. scsi_request_fn() prints about offline device also for sdev->sdev_state == SDEV_DEL. While scsi_prep_state_check() prints about a dead device in this case. Would it make sense to remove the redundant dev_printk() from scsi_request_fn()? Then we could add a flag into struct scsi_device that would remember if we already printed the error in scsi_prep_state_check() for the given device. It could be used to print the error only once. The flag might be scsi_device_state value for which we printed the error last time. We would need to reset it scsi_prep_state_check() see another state. It is a bit hairy but it really does not make much sense to print the same error message thousand times. Best Regards, Petr PS: Your mail was again strangely formatted. Please, send mails in plain text format (no html).
Re: 答复: Re: 答复: Re: [PATCH v2] scsi: Introduce sdev_printk_ratelimited tothrottlefrequent printk
On Mon 2018-04-09 10:13:43, wen.yan...@zte.com.cn wrote: > That's a good idea, but it only solves part of the problem. > loopping printks under spinlock, there's two path: > one path is: > scsi_request_fn --> loop -> blk_peek_request-> scsi_prep_fn -> > scsi_prep_state_check -> sdev_printk > another path is: > scsi_request_fn --> loop -> sdev_printk Is this message redundant? It seems to be printed in the same situations as the messages in scsi_prep_state_check(). In fact, there seems to be a mismatch. scsi_request_fn() prints about offline device also for sdev->sdev_state == SDEV_DEL. While scsi_prep_state_check() prints about a dead device in this case. Would it make sense to remove the redundant dev_printk() from scsi_request_fn()? Then we could add a flag into struct scsi_device that would remember if we already printed the error in scsi_prep_state_check() for the given device. It could be used to print the error only once. The flag might be scsi_device_state value for which we printed the error last time. We would need to reset it scsi_prep_state_check() see another state. It is a bit hairy but it really does not make much sense to print the same error message thousand times. Best Regards, Petr PS: Your mail was again strangely formatted. Please, send mails in plain text format (no html).
