Re: bug in sched.c:activate_task()

From: Nick Piggin
Date: Mon Oct 04 2004 - 22:18:55 EST


Con Kolivas wrote:

Chen, Kenneth W writes:

Update p->timestamp to "now" in activate_task() doesn't look right
to me at all. p->timestamp records last time it was running on a
cpu. activate_task shouldn't update that variable when it queues
a task on the runqueue.

This bug (and combined with others) triggers improper load balancing.


The updated timestamp was placed there by Ingo to detect on-runqueue time. If it is being used for load balancing then it is being used in error.


Load balancing wants to know if a task is considered cache hot.


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