On Wed, May 20, 2015 at 07:31:12PM +0100, Benjamin ESTRABAUD wrote: > After 25 iterations (after creating a 25GiB file, for a cumulative total of > 325GiB if including the testfile.1G -> testfile.24G) the issue occured > again. The IO rate to the SAN LUN dropped severely to a real 3MiB/sec > (measured at the SAN LUN block device level). > > Also I've noticed that a kernel process is taking up 100% of one core at > least: > > 516 root 20 0 0 0 0 R 100.0 0.0 11:09.72 > kworker/u49:4 Can you send me the output of "perf record -ag" for that run? Also can you send the output from trace-cmd for tracing all nfsd.layout* tracepoints for such a run? > Would the 25GiB figure ring any bells to you? Would there be a way for me to > identify this workqueue (figure out if it is pNFS related)? Perf record should help by looking at the cycles spent. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
