From owner-freebsd-hackers Thu Jan 31 16:49:43 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from inje.iskon.hr (inje.iskon.hr [213.191.128.16]) by hub.freebsd.org (Postfix) with ESMTP id 8008637B41A for ; Thu, 31 Jan 2002 16:49:36 -0800 (PST) Received: from tel.fer.hr (zg07-137.dialin.iskon.hr [213.191.150.138]) by mail.iskon.hr (8.11.4/8.11.4/Iskon 8.11.3-1) with ESMTP id g110lJg22878; Fri, 1 Feb 2002 01:47:21 +0100 (MET) Message-ID: <3C59E584.1F320CF8@tel.fer.hr> Date: Fri, 01 Feb 2002 01:47:01 +0100 From: Marko Zec X-Mailer: Mozilla 4.78 [en] (Windows NT 5.0; U) X-Accept-Language: en MIME-Version: 1.0 To: Storms of Perfection Cc: mjm@michaelmeltzer.com, silby@silby.com, thierry@herbelot.com, replicator@ngs.ru, hackers@FreeBSD.ORG Subject: Re: Clock Granularity (kernel option HZ) References: <005b01c1aaaf$e38ecd70$34f820c0@ix1x1000> <3503.208.141.46.249.1012522251.squirrel@test.outloud.org> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Storms of Perfection wrote: > Ok. Since I have a limited hardware/software set at my finger tips. I can > generate an attack on my machine (such as a synflood or something) to see > what type of reponses I can get by setting it up and down. I think this may > apply to this feature, to help the machine withstand attacks (and possibly > have performance related gains/decreases) Under no circumstances can increasing HZ make the machine less vulnerable to high packet-rate traffic. In fact, it will performe even slightly worse. Try using interrupt coalescing instead (on cards that support it), or even better, try Luigi's polling code. Marko To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message