On Friday, 07/21/2006 at 08:23 EST, Rich Smrcina <[EMAIL PROTECTED]> wrote: > spin_retry Kernel parameter > With this update an additional kernel-command line parameter is > provided. The default value is 0 for this parameter. Setting this > parameter to 1000 has shown for most workloads on a linux runnig under > z/VM that the number of DIAG 44 calls is significant reduced. > > Is this only related to multiple virtual CPUs or does it apply to any > workload?
Only multiple virtual CPUs. In a uniprocessor environment Linux shouldn't issue diag 44. > Has the performance impact of this change been measured? If so, what is it? Not a direct answer to your question, but for some information on the effects of z/VM 5.2 DIAG 44 Fast Path support, see http://www.vm.ibm.com/perf/reports/zvm/html/diag44.html. When combined with a reduction in diag 44s, you get a nice (technical term) performance improvement. Alan Altmark z/VM Development IBM Endicott ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
