RFR: Remove prefetch during mark

Aleksey Shipilev shade at redhat.com
Wed Feb 14 08:48:36 UTC 2018

On 02/14/2018 09:43 AM, Per Liden wrote:
> Small patch to remove the prefetch we do during marking. Charlie Hunt spent some time looking into
> the effect of this, and in conclusion the prefetch doesn't help.

Our Shenandoah experience corroborates this: once you lay out the objects in traversal order (or
some approximation of it), the mark prefetch becomes actively hostile: wastes cycles/instruction for
the accesses that are already implicitly-prefetched well.


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