From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: small RPS cache for fragments? Date: Tue, 17 May 2011 14:44:42 -0700 Message-ID: References: <20110517.143342.1566027350038182221.davem@davemloft.net> <1305663288.2691.2.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: David Miller , netdev@vger.kernel.org To: Eric Dumazet Return-path: Received: from mga01.intel.com ([192.55.52.88]:7338 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932308Ab1EQVpN (ORCPT ); Tue, 17 May 2011 17:45:13 -0400 In-Reply-To: <1305663288.2691.2.camel@edumazet-laptop> (Eric Dumazet's message of "Tue, 17 May 2011 22:14:48 +0200") Sender: netdev-owner@vger.kernel.org List-ID: Eric Dumazet writes: > > OK but do we have workloads actually needing this optimization at all ? That's a good a question. > > (IP defrag hits a read_lock(&ip4_frags.lock)), so maybe steer all frags > on a given cpu ?) Couldn't the lock just be replaced with a hashed or bitmap lock or bit in low bits of pointer lock? iirc it just protects the heads of the hash table. They're not rwlocks, but especially if the locking was more finegrained that's likely not needed anymore. -Andi -- ak@linux.intel.com -- Speaking for myself only