Hi all, this patchset implements a new SCSI EH command timeout handler which will be sending command aborts inline without actually engaging SCSI EH. SCSI EH will only be invoked if command abort fails.
In addition the commands will be returned directly if the command abort succeeded, cutting down recovery times dramatically. With the original SCSI EH I got: # time dd if=/dev/zero of=/dev/dm-2 bs=4k count=4k oflag=direct 4096+0 records in 4096+0 records out 16777216 bytes (17 MB) copied, 142.652 s, 118 kB/s real 2m22.657s user 0m0.013s sys 0m0.145s With this patchset I got: # time dd if=/dev/zero of=/dev/dm-2 bs=4k count=4k oflag=direct 4096+0 records in 4096+0 records out 16777216 bytes (17 MB) copied, 52.1579 s, 322 kB/s real 0m52.163s user 0m0.012s sys 0m0.145s Test was to disable RSCN on the target port, disable the target port, and then start the 'dd' command as indicated. Changes to the original version: - Use a private list in scsi_eh_abort_handler to avoid list starvation (pointed out by Joern Engel) - Terminate command aborts when the first abort fails - Do not attempt command aborts if the host is already in recovery or if the device is removed. - Flush abort workqueue if the device is removed. Changes to v2: - Removed eh_entry initialisation - Convert to per-command workqueue Changes to v3: - Use delayed_work - Enable new eh timeout handler for virtio, SAS, and FC - Modify logging messages to include scmd pointer Changes to v4: - Remove stubs when enabling new eh timeout handler for other drivers Changes to v5: - Enable new eh timeout handler per default - Update documentation Changes to v6: - Include changes from James Bottomley for erratic device offline patch - Rearrange patches - Update SCSI midlayer documentation Changes to v7: - Merge obsolete patch Hannes Reinecke (2): scsi: improved eh timeout handler scsi: Update documentation James Bottomley (1): scsi: Fix erratic device offline during EH Documentation/scsi/scsi_eh.txt | 69 +++++++------ Documentation/scsi/scsi_mid_low_api.txt | 9 +- drivers/scsi/scsi.c | 9 +- drivers/scsi/scsi_error.c | 178 ++++++++++++++++++++++++++++---- drivers/scsi/scsi_priv.h | 2 + drivers/scsi/sd.c | 26 +++-- include/scsi/scsi_cmnd.h | 2 + include/scsi/scsi_driver.h | 2 +- include/scsi/scsi_host.h | 5 + 9 files changed, 229 insertions(+), 73 deletions(-) -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
