<div dir="ltr">Looks like whitehole_spin is _not_ always 0. Contention just seems to be really rare.</div><div class="gmail_extra"><br><br><div class="gmail_quote">On Thu, Jul 25, 2013 at 1:32 PM, Patrick Palka <span dir="ltr"><<a href="mailto:patrick@parcs.ath.cx" target="_blank">patrick@parcs.ath.cx</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">It seems that the value of the whitehole_spin counter (as viewable by +RTS -s) is always zero, which oddly suggests that there is never any contention on the particular atomic operation whitehole_spin is tracking (located in copyPart in Evac.c). This may be a symptom of a bug, or it may be the case that the atomic operation is not necessary. (Or perhaps contention is just very rare. But if contention is rare, why is this operation being counted in particular?) Either way, I think this is a bit strange and probably worth investigating.<span class="HOEnZb"><font color="#888888"><div>
<div><br><div><div><div>Patrick</div></div></div></div></div></font></span></div>
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