Re: [PATCH 3/3] target: simplify target_wait_for_sess_cmds()

["Jörn Engel" <joern@logfs.org>]

On Mon, 13 May 2013 20:08:44 -0700, Nicholas A. Bellinger wrote:
> On Mon, 2013-05-13 at 18:00 -0400, Jörn Engel wrote:
> > 
> > I agree that the overhead doesn't matter.  The msleep(100) spells this
> > out rather explicitly.  What does matter is that a) the patch retains
> > old behaviour with much simpler code and b) it fixes a race that kills
> > the machine.  I can live without a, but very much want to keep b. ;)
> 
> Fucking around with ->sess_cmd_lock during each loop of ->sess_cmd_list
> in target_wait_for_sess_cmds is not simpler code..

I could argue that fucking around with ->sess_cmd_lock during each
loop is simpler than the communication through cmd_wait_set and
cmd_wait_comp.  But simplicity is ultimately subjective and we can
argue all day.

 drivers/infiniband/ulp/srpt/ib_srpt.c  |    2 +-
 drivers/scsi/qla2xxx/tcm_qla2xxx.c     |    2 +-
 drivers/target/target_core_transport.c |   64 +++++++++-----------------------
 include/target/target_core_base.h      |    2 -
 include/target/target_core_fabric.h    |    2 +-
 5 files changed, 20 insertions(+), 52 deletions(-)

But diffstat is reasonably objective.  Do you really want me to come
up with an alternative patch that adds code instead of removing it?

Jörn

--
Simplicity is prerequisite for reliability.
-- Edsger W. Dijkstra