Date: Tue, 5 Feb 2002 22:10:01 -0800 (PST) From: Vladimir Ivanov <wawa@yandex-team.ru> To: freebsd-bugs@FreeBSD.org Subject: Re: kern/34639: IPFW skipto works too slow Message-ID: <200202060610.g166A1642457@freefall.freebsd.org>
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The following reply was made to PR kern/34639; it has been noted by GNATS. From: Vladimir Ivanov <wawa@yandex-team.ru> To: Bill Fumerola <billf@mu.org> Cc: FreeBSD-gnats-submit@freebsd.org Subject: Re: kern/34639: IPFW skipto works too slow Date: Wed, 06 Feb 2002 09:07:34 +0300 Bill Fumerola wrote: > On Tue, Feb 05, 2002 at 05:53:19PM +0300, wawa@yandex-team.ru wrote: > > >>>Description: >>> >>The original implementation of skipto rule use brute-force to find the appropriate rule. >>The suggested implementation use indexed access. >> > > the ipfw code caches the skipto rule the first time it gets used. i don't > think cacheing it in a different spot really helps anything. I've never seen caching of skipto's in the code. Maybe the cacheing is very tricky. ;-) > > are you actually seeing performance problems? can you actually prove > that ipfw is faster with this change? > > Sure, I've tested it on a real system. The system was unable to process more than several hundred rules with skipto's. It was losing packets. 'top' utility reported about 99% CPU for 'interrupts' and the total bandwidth degradated twice after adding even only skipto rule in the tail of chain. The behaviour after applying patch is expected. Best regards, -- Vladimir Ivanov Network Operation Center OOO "Yandex" e-mail: noc@yandex.net (corporate) wawa@yandex-team.ru (personal) www: www.yandex.ru tel: +7 095 974-3555 fax: +7 095 974-3565 -- A diplomat is someone who can tell you to go to hell in such a way that you will look forward to the trip. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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