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From: Chris Friesen <cfriesen@nortelnetworks.com>
To: "Perez-Gonzalez, Inaky" <inaky.perez-gonzalez@intel.com>
Cc: george@mvista.com, root@chaos.analogic.com, "Brown,
	Len" <len.brown@intel.com>,
	Tim Schmielau <tim@physik3.uni-rostock.de>,
	john stultz <johnstul@us.ibm.com>,
	lkml <linux-kernel@vger.kernel.org>
Subject: Re: gradual timeofday overhaul
Date: Thu, 21 Oct 2004 16:36:38 -0600	[thread overview]
Message-ID: <417839F6.7090308@nortelnetworks.com> (raw)
In-Reply-To: <F989B1573A3A644BAB3920FBECA4D25A011F96DC@orsmsx407>

Perez-Gonzalez, Inaky wrote:

> Now, the ugly case would be if number_of_context_swiches_per_second > HZ.
> In HZ = 100, this could be happening, but in HZ=1000, in a single CPU
> ...well, that would be TOO weird [of course, a real-time app with a 
> 1ms period would do that, but it'd require at least an HZ of 10000 to
> work more or less ok and we'd be below the watermark].

It's easy to have >>1000 context switches per second on a server.  Consider a 
web server that receives a network packet, issues a request to a database, hands 
some work off to a thread so the main app doesn't block, then sends a response. 
  That could be a half dozen context switches per packet.  If you have 20000 
packets/sec coming in....


Chris

  reply	other threads:[~2004-10-21 22:51 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-10-21 21:32 gradual timeofday overhaul Perez-Gonzalez, Inaky
2004-10-21 22:36 ` Chris Friesen [this message]
2004-10-22  0:21 ` George Anzinger
  -- strict thread matches above, loose matches on Subject: below --
2004-10-22  0:29 Perez-Gonzalez, Inaky
2004-10-21  8:32 Perez-Gonzalez, Inaky
2004-10-21 21:17 ` George Anzinger
2004-10-21 22:40   ` Chris Friesen
2004-10-25 23:12     ` George Anzinger
2004-10-25 23:51       ` Chris Friesen
2004-10-19 18:21 process start time set wrongly at boot for kernel 2.6.9 Jerome Borsboom
2004-10-19 20:11 ` john stultz
2004-10-20  0:42   ` Tim Schmielau
2004-10-20  0:59     ` john stultz
2004-10-20  3:05       ` gradual timeofday overhaul Tim Schmielau
2004-10-20  7:47         ` Len Brown
2004-10-20 15:09           ` George Anzinger
2004-10-20 15:59             ` Richard B. Johnson
2004-10-20 15:17           ` George Anzinger
2004-10-20 17:09           ` Lee Revell
2004-10-20 21:42             ` Len Brown
2004-10-20 18:13         ` john stultz

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