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Date: Wed, 1 Aug 2018 09:55:40 +0000
From: Eric Wong <normalperson@yhbt.net>
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References: <redmine.issue-14718.20180427161410@ruby-lang.org>
 <redmine.journal-73261.20180801001429.9e802cfbff28d67b@ruby-lang.org>
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Subject: [ruby-core:88256] Re: [Ruby trunk Feature#14718] Use jemalloc by
 default?
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sam.saffron@gmail.com wrote:
> As much as we like to think of jemalloc as a silver bullet of
> sorts... there are problems... In particular if you have THP
> enabled which most people do out of the box its behavior is
> not ideal despite all the fixes it has gotten over the years.
> My observation is that both MALLOC_ARENA_MAX=2 and tcmalloc
> can perform better if THP is on, both in 5.1 and 3.6.0.
> Getting the world to turn off THP is a hard job. 

Ruby 2.6 will disable THP, at least:

   https://bugs.ruby-lang.org/issues/14705