diff options
| author | Christoph Hellwig <hch@lst.de> | 2014-01-22 15:29:29 +0100 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2014-07-25 07:43:43 -0400 |
| commit | 74665016086615bbaa3fa6f83af410a0a4e029ee (patch) | |
| tree | 9f9d8a692bec91dce69fd303eeedf16c35b41ac6 /drivers/scsi/scsi_error.c | |
| parent | 7ae65c0f9646c29432b69580b80e08632e6cd813 (diff) | |
scsi: convert host_busy to atomic_t
Avoid taking the host-wide host_lock to check the per-host queue limit.
Instead we do an atomic_inc_return early on to grab our slot in the queue,
and if necessary decrement it after finishing all checks.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>
Diffstat (limited to 'drivers/scsi/scsi_error.c')
| -rw-r--r-- | drivers/scsi/scsi_error.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index e4a532463f9a..5db8454474ee 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -59,7 +59,7 @@ static int scsi_try_to_abort_cmd(struct scsi_host_template *, /* called with shost->host_lock held */ void scsi_eh_wakeup(struct Scsi_Host *shost) { - if (shost->host_busy == shost->host_failed) { + if (atomic_read(&shost->host_busy) == shost->host_failed) { trace_scsi_eh_wakeup(shost); wake_up_process(shost->ehandler); SCSI_LOG_ERROR_RECOVERY(5, shost_printk(KERN_INFO, shost, @@ -2164,7 +2164,7 @@ int scsi_error_handler(void *data) while (!kthread_should_stop()) { set_current_state(TASK_INTERRUPTIBLE); if ((shost->host_failed == 0 && shost->host_eh_scheduled == 0) || - shost->host_failed != shost->host_busy) { + shost->host_failed != atomic_read(&shost->host_busy)) { SCSI_LOG_ERROR_RECOVERY(1, shost_printk(KERN_INFO, shost, "scsi_eh_%d: sleeping\n", @@ -2178,7 +2178,8 @@ int scsi_error_handler(void *data) shost_printk(KERN_INFO, shost, "scsi_eh_%d: waking up %d/%d/%d\n", shost->host_no, shost->host_eh_scheduled, - shost->host_failed, shost->host_busy)); + shost->host_failed, + atomic_read(&shost->host_busy))); /* * We have a host that is failing for some reason. Figure out |