From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 79FEFEE642D for ; Fri, 15 Sep 2023 07:09:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232590AbjIOHJ3 convert rfc822-to-8bit (ORCPT ); Fri, 15 Sep 2023 03:09:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232538AbjIOHJ3 (ORCPT ); Fri, 15 Sep 2023 03:09:29 -0400 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.85.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id D335AF3 for ; Fri, 15 Sep 2023 00:09:23 -0700 (PDT) Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with both STARTTLS and AUTH (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-198-t_eZK13gOEuJOSE7_IKRiA-1; Fri, 15 Sep 2023 08:09:16 +0100 X-MC-Unique: t_eZK13gOEuJOSE7_IKRiA-1 Received: from AcuMS.Aculab.com (10.202.163.6) by AcuMS.aculab.com (10.202.163.6) with Microsoft SMTP Server (TLS) id 15.0.1497.48; Fri, 15 Sep 2023 08:09:12 +0100 Received: from AcuMS.Aculab.com ([::1]) by AcuMS.aculab.com ([::1]) with mapi id 15.00.1497.048; Fri, 15 Sep 2023 08:09:12 +0100 From: David Laight To: 'David Howells' , Al Viro , Linus Torvalds CC: Jens Axboe , Christoph Hellwig , "Christian Brauner" , Matthew Wilcox , "Brendan Higgins" , David Gow , "linux-fsdevel@vger.kernel.org" , "linux-block@vger.kernel.org" , "linux-mm@kvack.org" , "netdev@vger.kernel.org" , "linux-kselftest@vger.kernel.org" , "kunit-dev@googlegroups.com" , "linux-kernel@vger.kernel.org" , Andrew Morton , Christian Brauner , David Hildenbrand , John Hubbard Subject: RE: [RFC PATCH 9/9] iov_iter: Add benchmarking kunit tests for UBUF/IOVEC Thread-Topic: [RFC PATCH 9/9] iov_iter: Add benchmarking kunit tests for UBUF/IOVEC Thread-Index: AQHZ51kQ26Nrcgq1TkqWWiI5nPv6dLAbdkPg Date: Fri, 15 Sep 2023 07:09:12 +0000 Message-ID: References: <20230914221526.3153402-1-dhowells@redhat.com> <20230914221526.3153402-10-dhowells@redhat.com> In-Reply-To: <20230914221526.3153402-10-dhowells@redhat.com> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: David Howells > Sent: 14 September 2023 23:15 > > Add kunit tests to benchmark 256MiB copies to a UBUF iterator and an IOVEC > iterator. This attaches a userspace VM with a mapped file in it > temporarily to the test thread. Isn't that going to be completely dominated by the cache fills from memory? I'd have thought you'd need to use something with a lot of small fragments so that the iteration code dominates the copy. Some measurements can be made using readv() and writev() on /dev/zero and /dev/null. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)