diff options
| author | Cathy Avery <cavery@redhat.com> | 2017-10-31 08:52:06 -0400 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2017-11-03 11:29:22 -0400 |
| commit | 436ad941335386c5fc7faa915a8fbdfe8c908084 (patch) | |
| tree | 3eb9e76bf92f384b8b7229ace9cdd00601b3a90e /tools/perf/scripts/python/stackcollapse.py | |
| parent | ca6958b4da8b7fd9f6ac3bf94def9cfb8a1d6c25 (diff) | |
scsi: storvsc: Allow only one remove lun work item to be issued per lun
When running multipath on a VM if all available paths go down the driver
can schedule large amounts of storvsc_remove_lun work items to the same
lun. In response to the failing paths typically storvsc responds by
taking host->scan_mutex and issuing a TUR per lun. If there has been
heavy IO to the failed device all the failed IOs are returned from the
host. A remove lun work item is issued per failed IO. If the outstanding
TURs have not been completed in a timely manner the scan_mutex is never
released or released too late. Consequently the many remove lun work
items are not completed as scsi_remove_device also tries to take
host->scan_mutex. This results in dragging the VM down and sometimes
completely.
This patch only allows one remove lun to be issued to a particular lun
while it is an instantiated member of the scsi stack.
Signed-off-by: Cathy Avery <cavery@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'tools/perf/scripts/python/stackcollapse.py')
0 files changed, 0 insertions, 0 deletions