> Erez Zilber wrote: > > Mike, > > > > I'm still investigating the performance problems in open-iscsi over iSER, > > and I think that I see the cause of the problem: > > > > I've added an outstanding commands counter. It's incremented when > > iscsi_queuecommand is called and decremented when iscsi_complete_command is > > called. After decrementing the counter, I save it's value in some global > > array. I print this array when iscsi_session_teardown is called. > > > >From what I see, in ~25% of command completions, the command queue is empty > >(i.e. outstanding_cmds = 0). This can explain the low throughput that I see > >with iSER. > > > > What could be the cause for that? Is there anything not well configured in > > the scsi_host_template that we use? Anything else? > > > > I saw this when using all io schedulers except noop. When I set the > queue to use noop, The iscsi queue was full (host_busy was greater than > 1) most of the time and thoughout was higher. I was going by just checking > > /sys/class/scsi_host/hostX/host_busy
I'm not familiar with "io schdulers". What's that? You're not talking about benchmraks, right? I wasn't aware of /sys/class/scsi_host/hostX/host_busy. I will take a look. > > which if I underatnd your patch right is similar to what you are doing. > > I will run your patch to double check though. > > Also I think you can tweak the other schedulers to fix the problem, but > I have not found the right combo yet. Again, if you can say a few more words about the schdulers. Where do I set it? Thanks, Erez --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/open-iscsi -~----------~----~----~----~------~----~------~--~---
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