netdev - Re: Extensible hashing and RCU

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 19 Feb 2007 13:26:42 -0500
From:	Benjamin LaHaise <bcrl@...ck.org>
To:	Eric Dumazet <dada1@...mosbay.com>
Cc:	Evgeniy Polyakov <johnpol@....mipt.ru>, akepner@....com,
	linux@...izon.com, davem@...emloft.net, netdev@...r.kernel.org
Subject: Re: Extensible hashing and RCU

On Mon, Feb 19, 2007 at 07:13:07PM +0100, Eric Dumazet wrote:
> So even with a lazy hash function, 89 % of lookups are satisfied with less 
> than 6 compares.

Which sucks, as those are typically going to be cache misses (costing many 
hundreds of cpu cycles).  Hash chains fair very poorly under DoS conditions, 
and must be removed under a heavy load.  Worst case handling is very 
important next to common case.

		-ben
-- 
"Time is of no importance, Mr. President, only life is important."
Don't Email: <dont@...ck.org>.
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html