Messages in this thread | | | Date | Tue, 24 Feb 2015 12:41:12 -0500 | From | Steven Rostedt <> | Subject | Re: RFC: revert 43fa5460fe60 |
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On Tue, 24 Feb 2015 09:19:06 -0800 Jörn Engel <joern@purestorage.com> wrote:
> Well, reverting was my first instinct, but for different reasons I think > it is wrong. Simply reverting can result in the high priority thread > moving from one cpu with a running process to a different cpu with a > running process. In both cases you may trip over a mole, so nothing > much is gained. > > But if you know that the destination cpu is idle, you can avoid any > moles, give or take a small race window maybe. The moles are still > present and you still need some debug tool to detect them and fix them > over time. But as cpus increase over time, your chances of getting > lucky in spite of bad kernel code also increase. > > Is that a worthwhile approach, at least for non PREEMPT?
I don't know. Could probably add it if CONFIG_PREEMPT is not set. Just check if an idle CPU is available in that case and move it, as non PREEMPT kernels will have long latencies anyway.
-- Steve
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