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authorBjorn Helgaas <bhelgaas@google.com>2016-08-01 12:34:01 -0500
committerBjorn Helgaas <bhelgaas@google.com>2016-08-01 12:34:01 -0500
commit9454c23852ca6d7aec89fd6fd46a046c323caac3 (patch)
tree794be65345027b5adea3720a43124fee338333a5 /Documentation/scsi/scsi_eh.txt
parenta04bee8285a71cdbb9076c3dc38be1f0b9a6b4b3 (diff)
parent4ef33685aa0957d771e068b60a5f3ca6b47ade1c (diff)
downloadlinux-9454c23852ca6d7aec89fd6fd46a046c323caac3.tar.gz
Merge branch 'pci/msi-affinity' into next
Conflicts:
	drivers/nvme/host/pci.c
Diffstat (limited to 'Documentation/scsi/scsi_eh.txt')
-rw-r--r--Documentation/scsi/scsi_eh.txt8
1 files changed, 6 insertions, 2 deletions
diff --git a/Documentation/scsi/scsi_eh.txt b/Documentation/scsi/scsi_eh.txt
index 8638f61c8c9d..37eca00796ee 100644
--- a/Documentation/scsi/scsi_eh.txt
+++ b/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