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From: Adrian Chadd <adrian.chadd@gmail.com>
Date: Sun, 31 Jul 2016 07:03:08 -0700
Message-ID: <CAJ-VmokxFFe4iAuMKEZuCjua4YUHx=PiXJKSBibsDKxWOrm7uA@mail.gmail.com>
Subject: Re: [PATCH] randomized delay in locking primitives, take 2
To: Mateusz Guzik <mjguzik@gmail.com>, John Baldwin <jhb@freebsd.org>, 
 freebsd-current <freebsd-current@freebsd.org>,
 Konstantin Belousov <kib@freebsd.org>
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Hi,

Did you test on any 1, 2, 4, 8 cpu machines? just to see if there are
any performance degredations on lower count CPUs?

Also, yeah, the MOD operator in each loop could get spendy on older
CPUs (eg my MIPS CPUs, older ARM stuff, etc.) Is it possible to
achieve much the same autotuning with pow2 operations instead of
divide/mod?


-a