On Thu, Aug 8, 2013 at 4:25 PM, Or Gerlitz <[email protected]> wrote: > Replace the session lock with two locks, a "forward" lock and > a "backwards" lock named frwd_lock and back_lock respectively. > > The forward lock protects resources that change while sending a > request to the target, such as cmdsn, queued_cmdsn, and allocating > task from the commands' pool with kfifo_out. > > The backward lock protects resources that change while processing > a response or in error path, such as cmdsn_exp, cmdsn_max, and > returning tasks to the commands' pool with kfifo_in. > > Under a "steady state" fast-path situation, that is when one > or more processes/threads submit IO to an iscsi device and > a single kernel upcall (e.g softirq) is dealing with processing > of responses without errors, this patch eliminates the contention > between the queuecommand()/request response/scsi_done() associated > with iscsi sessions. > > Using this patch in an accelerated version of the iser initiator we were > able to gain large improvements in IOPS rate in a situation where the burning > bottle-neck was the session lock.
Hi Mike and Co. Any feedback on this patch? Or. -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/groups/opt_out.
