From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f48.google.com (mail-pa0-f48.google.com [209.85.220.48]) by kanga.kvack.org (Postfix) with ESMTP id C40319003C7 for ; Wed, 22 Jul 2015 19:19:57 -0400 (EDT) Received: by padck2 with SMTP id ck2so145446760pad.0 for ; Wed, 22 Jul 2015 16:19:57 -0700 (PDT) Received: from aserp1040.oracle.com (aserp1040.oracle.com. [141.146.126.69]) by mx.google.com with ESMTPS id gs1si7092003pac.67.2015.07.22.16.19.55 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 22 Jul 2015 16:19:56 -0700 (PDT) Message-ID: <55B024C6.8010504@oracle.com> Date: Wed, 22 Jul 2015 16:18:30 -0700 From: Mike Kravetz MIME-Version: 1.0 Subject: Re: [PATCH v4 00/10] hugetlbfs: add fallocate support References: <1437502184-14269-1-git-send-email-mike.kravetz@oracle.com> <20150722150647.2597c7e5be9ee1eecc438b6f@linux-foundation.org> <1437603594.3298.5.camel@stgolabs.net> <20150722153023.e8f15eb4e490f79cc029c8cd@linux-foundation.org> In-Reply-To: <20150722153023.e8f15eb4e490f79cc029c8cd@linux-foundation.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton , Davidlohr Bueso , Eric B Munson Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Dave Hansen , Naoya Horiguchi , David Rientjes , Hugh Dickins , Aneesh Kumar , Hillf Danton , Christoph Hellwig , Michal Hocko On 07/22/2015 03:30 PM, Andrew Morton wrote: > On Wed, 22 Jul 2015 15:19:54 -0700 Davidlohr Bueso wrote: > >>> >>> I didn't know that libhugetlbfs has tests. I wonder if that makes >>> tools/testing/selftests/vm's hugetlbfstest harmful? >> >> Why harmful? Redundant, maybe(?). > > The presence of the in-kernel tests will cause people to add stuff to > them when it would be better if they were to apply that effort to > making libhugetlbfs better. Or vice versa. > > Mike's work is an example. Someone later makes a change to hugetlbfs, runs > the kernel selftest and says "yay, everything works", unaware that they > just broke fallocate support. > >> Does anyone even use selftests for >> hugetlbfs regression testing? Lets see, we also have these: >> >> - hugepage-{mmap,shm}.c >> - map_hugetlb.c >> >> There's probably a lot of room for improvement here. > > selftests is a pretty scrappy place. It's partly a dumping ground for > things so useful test code doesn't just get lost and bitrotted. Partly > a framework so people who add features can easily test them. Partly to > provide tools to architecture maintainers when they wire up new > syscalls and the like. > > Unless there's some good reason to retain the hugetlb part of > selftests, I'm thinking we should just remove it to avoid > distracting/misleading people. Or possibly move the libhugetlbfs test > code into the kernel tree and maintain it there. Adding Eric as he is the libhugetlbfs maintainer. I think removing the hugetlb selftests in the kernel and pointing people to libhugetlbfs is the way to go. From a very quick scan of the selftests, I would guess libhugetlbfs covers everything in those tests. I'm willing to verify the testing provided by selftests is included in libhugetlbfs, and remove selftests if that is the direction we want to take. -- Mike Kravetz -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org