Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933078AbbFIQpt (ORCPT ); Tue, 9 Jun 2015 12:45:49 -0400 Received: from mga03.intel.com ([134.134.136.65]:2887 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753374AbbFIQpk (ORCPT ); Tue, 9 Jun 2015 12:45:40 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.13,582,1427785200"; d="scan'208";a="740222259" From: "Jiang, Dave" To: "bhelgaas@google.com" CC: "Allen.Hubbe@emc.com" , "linux-kernel@vger.kernel.org" , "linux-pci@vger.kernel.org" , "jdmason@kudzu.us" , "linux-ntb@googlegroups.com" Subject: Re: [PATCH v3 18/18] NTB: Increase transport MTU to 64k from 16k Thread-Topic: [PATCH v3 18/18] NTB: Increase transport MTU to 64k from 16k Thread-Index: AQHQosN14y56flQ9jkSLEoBalfVfxJ2ky9QAgAALZ4A= Date: Tue, 9 Jun 2015 16:45:36 +0000 Message-ID: <1433868335.38406.111.camel@intel.com> References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [143.182.51.82] Content-Type: text/plain; charset="utf-8" Content-ID: <7DCF224B447D9A4AB84DFC0FF2BD3E76@intel.com> MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by nfs id t59Gjrc2029895 Content-Length: 1931 Lines: 54 On Tue, 2015-06-09 at 11:04 -0500, 'Bjorn Helgaas' via linux-ntb wrote: > On Tue, Jun 9, 2015 at 4:44 AM, Allen Hubbe > wrote: > > From: Dave Jiang > > > > Benchmarking showed significant performance increase going from MTU > > size > > of 64k from 16k. Changing the default. > > This changelog doesn't parse. I think you mean "going from MTU size > 16k to 64k." Yes. Sorry about the confusion. > > The original value was 0x401e (16k + 0x1e), and the new value is > exactly 64k. Please include a note about what that extra 0x1e was > for > and why it isn't needed in the new value. Jon, can you comment on why there's the additional 30 bytes on top of 16k in the previous value? > > > Signed-off-by: Dave Jiang > > --- > > drivers/ntb/ntb_transport.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/ntb/ntb_transport.c > > b/drivers/ntb/ntb_transport.c > > index ea237aeca28c..c87bc0cbd607 100644 > > --- a/drivers/ntb/ntb_transport.c > > +++ b/drivers/ntb/ntb_transport.c > > @@ -76,7 +76,7 @@ static unsigned long max_mw_size; > > module_param(max_mw_size, ulong, 0644); > > MODULE_PARM_DESC(max_mw_size, "Limit size of large memory > > windows"); > > > > -static unsigned int transport_mtu = 0x401E; > > +static unsigned int transport_mtu = 0x10000; > > module_param(transport_mtu, uint, 0644); > > MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport > > packets"); > > > > -- > > 2.4.0.rc0.43.gcf8a8c6 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux > > -pci" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?