From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7B0653BB5B for ; Wed, 15 Nov 2023 16:40:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="CBHC/CA0" Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 40F111FDA for ; Wed, 15 Nov 2023 08:39:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1700066394; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=HCpNMTIKyOeROsc7/RWOAvMZhqSI0z3duXfnje8m3KQ=; b=CBHC/CA0M0yuJmdrlDFc38PPvdba8DEtaO4YXIgf8r1qNwIXXVGILgHCP5HeQ26hwsd25g YjoW43HWvYYHiwd7TwBOhygVm+GxAMFObTKJdBM5l8ZcwDnEcJIvFz95Xi9UipsWlt3Kcn kfynip3zZEJac1c50mT0a/9/ZWNecfw= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-121-UdDnholkMuG4DRRASuNUrQ-1; Wed, 15 Nov 2023 11:39:50 -0500 X-MC-Unique: UdDnholkMuG4DRRASuNUrQ-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id E6F20101B04B; Wed, 15 Nov 2023 16:39:46 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.16]) by smtp.corp.redhat.com (Postfix) with ESMTP id F0B85492BE8; Wed, 15 Nov 2023 16:39:33 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <20231115154946.3933808-1-dhowells@redhat.com> <20231115154946.3933808-6-dhowells@redhat.com> To: Linus Torvalds Cc: dhowells@redhat.com, Christian Brauner , Jens Axboe , Al Viro , Christoph Hellwig , David Laight , 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 , Huacai Chen , WANG Xuerui , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , loongarch@lists.linux.dev, linux-s390@vger.kernel.org Subject: Re: [PATCH v3 05/10] iov_iter: Create a function to prepare userspace VM for UBUF/IOVEC tests Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <3936725.1700066370.1@warthog.procyon.org.uk> Date: Wed, 15 Nov 2023 16:39:30 +0000 Message-ID: <3936726.1700066370@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.9 Linus Torvalds wrote: > From a quick look, what you were doing was checking that the patterns > you set up in user space came through ok. Dammit, what's wrong with > just using read()/write() on a pipe, or splice, or whatever. It will > test exactly the same iov_iter thing. I was trying to make it possible to do these tests before starting userspace as there's a good chance that if the UBUF/IOVEC iterators don't work right then your system can't be booted. Anyway, if I drop patches 5, 6, 7 and 10 (ie. the ones doing stuff with UBUF and IOVEC-type iterators), would you be okay with the rest? David