This patchset is against Martin Petersen's (mkp) repository: https://git.kernel.org/pub/scm/linux/kernel/git/mkp/linux.git branch: 4.19/scsi Note: this is not the repository mkp uses for normal SCSI subsystem submissions (whose url ends with .../mkp/scsi.git). Note 2: even though the branch is called "4.19/scsi" it contains a somewhat dated lk 4.17.0-rc1.
This patchset is on top of patches already made in this repository (and not in the mainline) to decrease the overhead that the sd driver adds in the sd_init_command() submission and the sd_done() response handling. On my laptop (i5-7200U) the submission path improved from around 380 nanoseconds per submission (mainline: lk 4.18.0-rc7) to 280 nanoseconds (mkp's repo (4.17.0-rc1) with this patchset). There was no measurable improvement from the work on the response path (i.e. sd_done()). It was tested with sgp_dd and the scsi_debug driver. Douglas Gilbert (5): add tweakable bounds_check flag, now off by default break sd_done sense processing out to own function streamline REQ_OP_READ-WRITE access streamline some logical operations make sd_done() REQ_OP_FLUSH handling explicit drivers/scsi/sd.c | 273 +++++++++++++++++++++++++++++----------------- drivers/scsi/sd.h | 1 + 2 files changed, 174 insertions(+), 100 deletions(-) -- 2.17.1
