X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2FDocumentation%2Fscsi%2Fscsi_eh.txt;fp=kernel%2FDocumentation%2Fscsi%2Fscsi_eh.txt;h=37eca00796eeebf805afbbf1504753c1a0febec0;hb=52f993b8e89487ec9ee15a7fb4979e0f09a45b27;hp=8638f61c8c9db70d767302497d417be6c9a0a030;hpb=c189ccac5702322ed843fe17057035b7222a59b6;p=kvmfornfv.git

diff --git a/kernel/Documentation/scsi/scsi_eh.txt b/kernel/Documentation/scsi/scsi_eh.txt
index 8638f61c8..37eca0079 100644
--- a/kernel/Documentation/scsi/scsi_eh.txt
+++ b/kernel/Documentation/scsi/scsi_eh.txt
@@ -263,19 +263,23 @@ scmd->allowed.
 
  3. scmd recovered
     ACTION: scsi_eh_finish_cmd() is invoked to EH-finish scmd
-	- shost->host_failed--
 	- clear scmd->eh_eflags
 	- scsi_setup_cmd_retry()
 	- move from local eh_work_q to local eh_done_q
     LOCKING: none
+    CONCURRENCY: at most one thread per separate eh_work_q to
+		 keep queue manipulation lockless
 
  4. EH completes
     ACTION: scsi_eh_flush_done_q() retries scmds or notifies upper
-	    layer of failure.
+	    layer of failure. May be called concurrently but must have
+	    a no more than one thread per separate eh_work_q to
+	    manipulate the queue locklessly
 	- scmd is removed from eh_done_q and scmd->eh_entry is cleared
 	- if retry is necessary, scmd is requeued using
           scsi_queue_insert()
 	- otherwise, scsi_finish_command() is invoked for scmd
+	- zero shost->host_failed
     LOCKING: queue or finish function performs appropriate locking