Messages in this thread | | | Date | Fri, 9 Sep 2016 09:44:56 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH RFC v6] x86,mm,sched: make lazy TLB mode even lazier |
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On Thu, Sep 08, 2016 at 09:39:45PM -0700, Andy Lutomirski wrote: > If they're busy threads, shouldn't the yield return immediately > because the threads are still ready to run? Lazy TLB won't do much > unless you get the kernel in some state where it's running in the > context of a different kernel thread and hasn't switched to > swapper_pg_dir. IIRC idle works like that, but you'd need to actually > sleep to go idle.
Right, a task doing:
for (;;) sched_yield();
esp. when its the only runnable thread on the CPU, is a busy thread. It will not enter switch_mm(), which was where the invalidate hook was placed IIRC.
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