Date: Tue, 21 Aug 2018 19:06:18 +0200 From: Support SimpleRezo <simplerezo@gmail.com> To: freebsd-virtualization@freebsd.org Subject: [HyperV-2016] urandom performance issue... Message-ID: <CALVu1vZ3iSFDt60mLVie_17rejNeXggjDOGdY7HuYeRGmMxM=w@mail.gmail.com>
next in thread | raw e-mail | index | archive | help
Hi list! I was figuring a performance issue of a FreeBSD on HyperV, after: - moving it from an Hyper-V 2012 host to a Hyper-V 2016 - updating to FreeBSD 11.2 (custom kernel, but same issue with GENERIC) After loosing some times because i was thinking about hardware issue (disk controller was my first thought...) and testing with "dd if=/dev/urandom"... I discovered this... I ran the following test... and quite surprised by the speed result! $ dd if=/dev/urandom of=/dev/null bs=10M count=3 3+0 records in 3+0 records out 31457280 bytes transferred in 27.960431 secs (1125064 bytes/sec) The test was also sometimes "freezing" the Hyper-V host! Looking into "dmesg" i have found this: random: registering fast source Intel Secure Key RNG random: fast provider: "Intel Secure Key RNG" So I rebuilt my KERNEL without "rdrand_rng" (didn't find another way to disable it...)... and performances went back to normal! I think this issue should documented on https://wiki.freebsd.org/HyperV ! Regards -- Clement SimpleRezo
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CALVu1vZ3iSFDt60mLVie_17rejNeXggjDOGdY7HuYeRGmMxM=w>