From: Hardik H Bagdi <hbagdi1@binghamton.edu>
To: kvm@vger.kernel.org
Subject: Limit of 160 for number of VCPUsin the guest
Date: Fri, 19 Feb 2016 18:16:42 -0500 [thread overview]
Message-ID: <CADdiZBQcP2rRNcZWKFHxxKtt47YYjzcsnp-L7SA6SD2qFFtf2Q@mail.gmail.com> (raw)
Hello,
For research, I am experimenting with increasing the number of VCPUs
in the guest OS.
I always get the following warning whenever I increased the number of
VCPUs beyond 160.
"Warning: Number of SMP cpus requested (250) exceeds the recommended
cpus supported by KVM (160)
Warning: Number of hot-pluggable cpus requested (250) exceeds the
recommended cpus supported by KVM (160)"
I also observed that the performance of sysbench CPU benchmark
degrades exponentially exactly beyond 160 VCPUs.
Can anyone explain what is so special about this 160 VCPUs limit that
causes this performance degradation?
Obviously someone else must also have experimented and hence
recommended that 160VCPUs limit in the warning.
Thank you,
Hardik Bagdi
reply other threads:[~2016-02-19 23:17 UTC|newest]
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