On 4/30/19 11:39 PM, Bart Van Assche wrote:
As explained during the 2018 LSF/MM session about increasing SCSI disk probing concurrency, the problems with the current probing approach are as follows:- The driver core is unaware of asynchronous SCSI LUN probing. wait_for_device_probe() waits for all asynchronous probes except asynchronous SCSI disk probes. - There is unnecessary serialization between sd_probe() and sd_remove(). This can lead to a deadlock. Hence this patch that modifies the sd driver such that it uses the driver core framework for asynchronous probing. The async domain and get_device()/put_device() pairs that became superfluous due to this change are removed. This patch does not affect the time needed for loading the scsi_debug kernel module with parameters delay=0 and max_luns=256. This patch depends on commit ef0ff68351be ("driver core: Probe devices asynchronously instead of the driver") that went upstream in kernel version v5.1-rc1. Cc: Lee Duncan <[email protected]> Cc: Hannes Reinecke <[email protected]> Cc: Luis Chamberlain <[email protected]> Cc: Johannes Thumshirn <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Pavel Machek <[email protected]> Cc: Dan Williams <[email protected]> Signed-off-by: Bart Van Assche <[email protected]> --- drivers/scsi/scsi.c | 12 +++--------- drivers/scsi/scsi_pm.c | 6 +----- drivers/scsi/scsi_priv.h | 1 - drivers/scsi/sd.c | 12 +++--------- 4 files changed, 7 insertions(+), 24 deletions(-)
Reviewed-by: Hannes Reinecke <[email protected]> Cheers, Hannes
