Re: Can context switches be faster?

From: Alan Cox
Date: Fri Oct 13 2006 - 20:04:18 EST


Ar Sad, 2006-10-14 am 01:32 +0200, ysgrifennodd Andreas Mohr:
> OK, so since we've now amply worked out in this thread that TLB/cache flushing
> is a real problem for context switching management, would it be possible to
> smartly reorder processes on the runqueue (probably works best with many active
> processes with the same/similar priority on the runqueue!) to minimize
> TLB flushing needs due to less mm context differences of adjacently scheduled
> processes?

We already do. The newer x86 processors also have TLB tagging so they
can (if you find one without errata!) avoid the actual flush and instead
track the tag.

Alan
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