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Opened 10 years ago

Closed 10 years ago

Last modified 9 years ago

#225 closed defect (wontfix)

After merge measuring branch to mainline top echoes weird load

Reported by: Stanislav Kozina Owned by: Martin Decky
Priority: major Milestone: 0.4.3
Component: helenos/unspecified Version: mainline
Keywords: Cc:
Blocker for: Depends on:
See also:

Description (last modified by Martin Decky)

Top from measuring branch echoes load between 0-1 immediately after system starts, which looks good.
After merge to mainline branch it echoes load sometimes bigger than 40, which is definitely wrong.

Change History (2)

comment:1 Changed 10 years ago by Martin Decky

Resolution: wontfix
Status: newclosed

I believe that the load values are perfectly reasonably — there is a lot of work happening just during the bootstrap process. For some reason the load calculating task gets scheduled a bit later in the measuring branch and misses this huge peak (this can be easily emulated by adding thread_sleep(1) at the beginning of the load calculating thread in mainline).

The problem comes from the fact that the load value is sampled just once during the whole 5 second period in this classical algorithm. Perhaps a completely different algorithm might be more suitable for a microkernel system with a lot of context switches (like recording the maximum ready queue length in the scheduler during the whole period).

I close this ticket for now. If you really believe that there is a specific bug in the mainline (which I really can't spot), feel free to reopen it.

comment:2 Changed 9 years ago by Martin Decky

Description: modified (diff)
Summary: After merge measuring branch to head top echoes weird loadAfter merge measuring branch to mainline top echoes weird load
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