Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752502Ab0DFFmU (ORCPT ); Tue, 6 Apr 2010 01:42:20 -0400 Received: from mga01.intel.com ([192.55.52.88]:33966 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752164Ab0DFFmP convert rfc822-to-8bit (ORCPT ); Tue, 6 Apr 2010 01:42:15 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.51,370,1267430400"; d="scan'208";a="786724901" From: "Xin, Xiaohui" To: "Michael S. Tsirkin" CC: "netdev@vger.kernel.org" , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "mingo@elte.hu" , "jdike@c2.user-mode-linux.org" , "yzhao81@gmail.com" Date: Tue, 6 Apr 2010 13:41:37 +0800 Subject: RE: [PATCH 1/3] A device for zero-copy based on KVM virtio-net. Thread-Topic: [PATCH 1/3] A device for zero-copy based on KVM virtio-net. Thread-Index: AcrRjDzWloLq/tseTwCC82REc7j2hQDvqoFg Message-ID: <97F6D3BD476C464182C1B7BABF0B0AF5C17B5BB9@shzsmsx502.ccr.corp.intel.com> References: <20100308112849.GI7482@redhat.com> <1270114038-5048-1-git-send-email-xiaohui.xin@intel.com> <20100401110841.GE3323@redhat.com> In-Reply-To: <20100401110841.GE3323@redhat.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 854 Lines: 23 Michael, >> >>For the DOS issue, I'm not sure how much the limit get_user_pages() >> can pin is reasonable, should we compute the bindwidth to make it? >There's a ulimit for locked memory. Can we use this, decreasing >the value for rlimit array? We can do this when backend is >enabled and re-increment when backend is disabled. I have tried it with rlim[RLIMIT_MEMLOCK].rlim_cur, but I found the initial value for it is 0x10000, after right shift PAGE_SHIFT, it's only 16 pages we can lock then, it seems too small, since the guest virito-net driver may submit a lot requests one time. Thanks Xiaohui -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/