Any reason you can't just use iostat or collectl or any of a number of
other standards tools to look at disk utilization?
On 08/29/2016 10:33 AM, Aaron Knister wrote:
Hi Everyone,
Would it be easy to have GPFS report iowait values in linux? This would
be a huge help for us in determining whether a node's low utilization is
due to some issue with the code running on it or if it's blocked on I/O,
especially in a historical context.
I naively tried on a test system changing schedule() in
cxiWaitEventWait() on line ~2832 in gpl-linux/cxiSystem.c to this:
again:
/* call the scheduler */
if ( waitFlags & INTERRUPTIBLE )
schedule();
else
io_schedule();
Seems to actually do what I'm after but generally bad things happen when
I start pretending I'm a kernel developer.
Any thoughts? If I open an RFE would this be something that's relatively
easy to implement (not asking for a commitment *to* implement it, just
that I'm not asking for something seemingly simple that's actually
fairly hard to implement)?
-Aaron
--
Alex Chekholko ch...@stanford.edu
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