#15585: IO stall for a long time during creation or deletion of many small files
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Reporter: X512 | Owner: nobody
Type: bug | Status: new
Priority: normal | Milestone: Unscheduled
Component: System/Kernel | Version: R1/Development
Resolution: | Keywords:
Blocked By: | Blocking:
Has a Patch: 0 | Platform: All
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Comment (by ambroff):
Oops, accidentally sent my last comment before finishing it. This report
sounds similar to some behavior I was noticing last year that lead me down
the path of digging in to I/O on haiku to understand how it works. I sent
an email about it to the list [https://www.freelists.org/post/haiku-
development/IO-Scheduler-experiment here].
I was curious to see if I would get the same kind of results that you do
X512 so I tried running it on one of my systems and the results are pretty
comperable. With a SATA spinning disk I'm seeing 5+ second pauses.
I only had limited time for this today so I don't have anything else
interesting to offer. Out of curiosity I tried running your benchmark with
the
[https://github.com/ambroff/haiku/blob/iostats/src/system/kernel/device_manager/IOSchedulerNoop.h#L100
IOSchedulerNoop experiment] I had started. I attached the results as plot-
IOSchedulerNoop-comparison.
The latency is definitely a lot flatter with IOSchedulerNoop, but that
doesn't necessarily mean that this is the main problem. That
implementation is also not finished. I just thought that would be an
interesting data point.
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Ticket URL: <https://dev.haiku-os.org/ticket/15585#comment:17>
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