Date: Wed, 15 Jun 2005 21:24:46 -0600 (MDT) From: "M. Warner Losh" <imp@bsdimp.com> To: jeremie@le-hen.org Cc: freebsd-current@freebsd.org Subject: Re: incorrect ping(8) interval with powerd(8) Message-ID: <20050615.212446.29494502.imp@bsdimp.com> In-Reply-To: <20050615231823.GB2239@obiwan.tataz.chchile.org> References: <20050615231823.GB2239@obiwan.tataz.chchile.org>
next in thread | previous in thread | raw e-mail | index | archive | help
In message: <20050615231823.GB2239@obiwan.tataz.chchile.org>
Jeremie Le Hen <jeremie@le-hen.org> writes:
: Hi list,
:
: as the subjects state, when powerd(8) is running and has set a lower
: frequency than the processor's natural one, interval between each
: packets are too long. When my laptop is plugged, I told powerd(8) to
: run the processor at maximum speed (-a max).
:
: Let's have a look at this :
: %%%
: jarjarbinks:root# sysctl hw.acpi.acline
: hw.acpi.acline: 1
: jarjarbinks:root# sysctl dev.cpu.0.freq
: dev.cpu.0.freq: 1735
: jarjarbinks:root# time ping -qc 2 192.168.1.1
: PING 192.168.1.1 (192.168.1.1): 56 data bytes
:
: --- 192.168.1.1 ping statistics ---
: 2 packets transmitted, 2 packets received, 0% packet loss
: round-trip min/avg/max/stddev = 0.266/0.269/0.271/0.002 ms
:
: real 0m1.003s
: user 0m0.001s
: sys 0m0.001s
:
: jarjarbinks:root# sysctl hw.acpi.acline
: hw.acpi.acline: 0
: jarjarbinks:root# sysctl dev.cpu.0.freq
: dev.cpu.0.freq: 216
: jarjarbinks:root# time ping -qc 2 192.168.1.1
: PING 192.168.1.1 (192.168.1.1): 56 data bytes
:
: --- 192.168.1.1 ping statistics ---
: 2 packets transmitted, 2 packets received, 0% packet loss
: round-trip min/avg/max/stddev = 0.637/0.814/0.991/0.177 ms
:
: real 0m2.252s
: user 0m0.004s
: sys 0m0.021s
: %%%
:
: I check ping(8) source code and it appears it uses select(8) to wait
: the desired amount of time. I don't think this is the intended
: behaviour. Where does this bug (feature?) come from ?
Those numbers look about right for a 200MHz CPU.
Warner
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20050615.212446.29494502.imp>