Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 25 Feb 2015 08:09:39 -0700
From:      Warner Losh <imp@bsdimp.com>
To:        Konstantin Belousov <kostikbel@gmail.com>
Cc:        Harrison Grundy <harrison.grundy@astrodoggroup.com>, freebsd-arch@freebsd.org
Subject:   Re: locks and kernel randomness...
Message-ID:  <3A406DF7-E6A1-494D-9B7D-3666D41DBC2B@bsdimp.com>
In-Reply-To: <20150225085659.GA74514@kib.kiev.ua>
References:  <DD06E2EA-68D6-43D7-AA17-FB230750E55A@bsdimp.com> <20150224174053.GG46794@funkthat.com> <54ECBD4B.6000007@freebsd.org> <20150224182507.GI46794@funkthat.com> <54ECEA43.2080008@freebsd.org> <20150224231921.GQ46794@funkthat.com> <CAHM0Q_NhUpr_HJZZcAEoZ_hNvZKcVzUBH-7LALsbkgqjLimA7A@mail.gmail.com> <20150225002301.GS46794@funkthat.com> <54ED80BD.1080603@freebsd.org> <54ED87E9.8030706@astrodoggroup.com> <20150225085659.GA74514@kib.kiev.ua>

next in thread | previous in thread | raw e-mail | index | archive | help

> On Feb 25, 2015, at 1:56 AM, Konstantin Belousov <kostikbel@gmail.com> =
wrote:
> So neither buildworld timing, nor network throughput are adequate
> to estimate the change.  It is system unresponsivness and loss of
> the realtime behaviour up to some degree.

Yes. You need to look at the changes affects, if any, on outlier =
behavior under load.
Without careful monitoring of that, you won=E2=80=99t see the bad =
effects. I=E2=80=99ve made several
changes over the years to improve performance that I later (usually much =
later) had
to back out or modify because it made the outlier behavior much worse.

So data here isn=E2=80=99t =E2=80=9CI did 3 build worlds and the time =
was about the same=E2=80=9D even if ministat(8)
says there=E2=80=99s no difference.

Warner




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?3A406DF7-E6A1-494D-9B7D-3666D41DBC2B>