From mboxrd@z Thu Jan  1 00:00:00 1970
From: bugzilla@dpdk.org
Subject: [Bug 48] Unexpected performance regression since
 CVE-2018-1059 fix with vector path
Date: Fri, 18 May 2018 16:01:41 +0000
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https://dpdk.org/tracker/show_bug.cgi?id=3D48

            Bug ID: 48
           Summary: Unexpected performance regression since CVE-2018-1059
                    fix with vector path
           Product: DPDK
           Version: 18.05
          Hardware: All
                OS: All
            Status: CONFIRMED
          Severity: normal
          Priority: Normal
         Component: vhost/virtio
          Assignee: dev@dpdk.org
          Reporter: maxime.coquelin@redhat.com
  Target Milestone: ---

A small performance drop was expected with CVE-2018-1059 fix integration.
While this expectation is verified for mast cases (less than 3% drop), a bi=
gger
drop is seen when using vector path in guest with small packets.

The goal of this ticket is to see if this performance regression can be=20
improved.=20

For reference, below is a copy paste from Lei Yao mail reporting the issue:

During the 18.05-rc1 performance testing, I find this patch set will bring
slightly performance drop on mergeable and normal path, and big performance
drop on vector path. Could you have a check on this? I know this patch is=20
important for security. Not sure if there is any way to improve the
performance.

Mergebale=20=20=20=20=20=20=20
packet size=20=20=20=20=20
64      0.80%
128     -2.75%
260     -2.93%
520     -2.72%
1024    -1.18%
1500    -0.65%

Normal=20=20
packet size=20=20=20=20=20
64      -1.47%
128     -7.43%
260     -3.66%
520     -2.52%
1024    -1.19%
1500    -0.78%

Vector=20=20
packet size=20=20=20=20=20
64      -8.60%
128     -3.54%
260     -2.63%
520     -6.12%
1024    -1.05%
1500    -1.20%=20

CPU info: Intel(R) Xeon(R) CPU E5-2699 v4 @ 2.20GHz
OS: Ubuntu 16.04

--=20
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