Messages in this thread |  | | Date | Tue, 3 Apr 2018 11:58:34 -0700 | From | "Luck, Tony" <> | Subject | Re: v4.16+ seeing many unaligned access in dequeue_task_fair() on IA64 |
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On Tue, Apr 03, 2018 at 09:37:06AM +0200, Peter Zijlstra wrote: > On Mon, Apr 02, 2018 at 04:24:49PM -0700, Luck, Tony wrote: > > Any guesses before I start to bisect? > > That doesn't sound good. The only guess I have at this moment is you > accidentially enabled RANDSTRUCT_PLUGIN and that messes things up. > > struct task_struct whould be at least L1_CACHE_BYTES aligned, and C > otherwise makes it fairly hard to cause unaligned accesses. Packed > structures and/or casting are required, and I don't think we added > anything dodgy like that here.
bisect says:
d519329f72a6 ("sched/fair: Update util_est only on util_avg updates")
Reverting just this commit makes the problem go away.
-Tony
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