From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin LaHaise Subject: Re: [RFC PATCH] fib_hash: improve route deletion scaling on interface drop with lots of interfaces Date: Tue, 27 Oct 2009 10:24:26 -0400 Message-ID: <20091027142426.GB3141@kvack.org> References: <20091027000302.GA3141@kvack.org> <20091026.171749.106971240.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org To: David Miller Return-path: Received: from kanga.kvack.org ([205.233.56.17]:33227 "EHLO kanga.kvack.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752947AbZJ0OYX (ORCPT ); Tue, 27 Oct 2009 10:24:23 -0400 Content-Disposition: inline In-Reply-To: <20091026.171749.106971240.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, Oct 26, 2009 at 05:17:49PM -0700, David Miller wrote: > > bottleneck. Next up in the network code is rt_cache_flush(). Comments? > > On a real router adding and removing routes is happening a lot > whereas interface changes are rare. You're making a more common > operation more expensive for the sake of a less common one. It's not a question of more common vs less common, but if the system can recover from an adverse event within a reasonable amount of time. Tunnel flaps occur in the real world, and this results in the change of state of a large number of interfaces at the same time. Would it be okay if this is wrapped in a config option? I agree that the extra overhead is not for everyone. > Please put local variable lines that are longer at the beginning of > the list of variable declarations at the top of a function, not the > other way around which stands out like a sore thumb and looks ugly. Whoops, will fix. -ben