From: Zdenek Kabelac <zkabelac@redhat.com>
To: LKML <linux-kernel@vger.kernel.org>,
Mike Snitzer <snitzer@redhat.com>,
Mikulas Patocka <mpatocka@redhat.com>,
Alasdair G Kergon <agk@redhat.com>,
viro@zeniv.linux.org.uk
Subject: Timing performance regression 4.15 to 4.16-rc1
Date: Sun, 11 Mar 2018 14:02:03 +0100 [thread overview]
Message-ID: <31a4b0d7-2c9e-ce76-a486-48ed18b96cc6@redhat.com> (raw)
Hi
I've noticed quite some drop of performance (around 15% in some cases) where
execution of lvm2 tests took longer time - and while tests itself should not
really load CPU system - the overall running time just got bigger.
Running bisect game pointed clearly to this commit:
---
commit 44c02a2c3dc55835e9f0d8ef73966406cd805001
Author: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu Oct 5 12:59:44 2017 -0400
dev_ioctl(): move copyin/copyout to callers
---
clear revert of this commit on top of 3266b5bd97eaa72793df0b6e5a106c69ccc166c4
(recent ~4.16-rc4) restored timing of tests back.
I'm not sure why - so at this moment this is just a patch causing 15% longer
running times on lvm2 test suite.
Regards
Zdenek
next reply other threads:[~2018-03-11 13:02 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-11 13:02 Zdenek Kabelac [this message]
2018-03-13 4:03 ` Al Viro
2018-03-13 11:17 ` Zdenek Kabelac
2018-03-13 16:45 ` Zdenek Kabelac
2018-03-13 21:46 ` Zdenek Kabelac
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