From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-next] udp: do rmem bulk free even if the rx sk queue is empty Date: Wed, 20 Sep 2017 14:29:14 -0700 (PDT) Message-ID: <20170920.142914.865968677643614093.davem@davemloft.net> References: Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, edumazet@google.com To: pabeni@redhat.com Return-path: Received: from shards.monkeyblade.net ([184.105.139.130]:38548 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751586AbdITV3P (ORCPT ); Wed, 20 Sep 2017 17:29:15 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: From: Paolo Abeni Date: Tue, 19 Sep 2017 12:11:43 +0200 > The commit 6b229cf77d68 ("udp: add batching to udp_rmem_release()") > reduced greatly the cacheline contention between the BH and the US > reader batching the rmem updates in most scenarios. > > Such optimization is explicitly avoided if the US reader is faster > then BH processing. > > My fault, I initially suggested this kind of behavior due to concerns > of possible regressions with small sk_rcvbuf values. Tests showed > such concerns are misplaced, so this commit relaxes the condition > for rmem bulk updates, obtaining small but measurable performance > gain in the scenario described above. > > Signed-off-by: Paolo Abeni Applied, thanks Paolo.