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 504A7C61DA4 for ; Mon, 30 Jan 2023 11:25:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236555AbjA3LZJ (ORCPT ); Mon, 30 Jan 2023 06:25:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60210 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231358AbjA3LZI (ORCPT ); Mon, 30 Jan 2023 06:25:08 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D703D1B575 for ; Mon, 30 Jan 2023 03:24:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1675077863; 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=w9A1bVyZb4er6cTd4zzjsltmhyvgIyU7DAJ3a6jVt6A=; b=BFZ3AtmuXs31O5WA6Ec4BZqFcMe3FI/HXBEb3MNLsMo1QBr1WfAA1iX4lI5EU+MoO+CEiO tQ0OvDojhL5YlupBvZdQL4iRIvvdyK3b1gSD2FI7bF6gpOn+8nYTt5f45MvJEmeBR48WRQ eUEvndQkM755qQ4yW0RAv094X4/y4es= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-102-JYIlhA5gM_SRvbpUiBK1og-1; Mon, 30 Jan 2023 06:24:18 -0500 X-MC-Unique: JYIlhA5gM_SRvbpUiBK1og-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 15A29382C965; Mon, 30 Jan 2023 11:24:18 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.97]) by smtp.corp.redhat.com (Postfix) with ESMTP id 27FB8492B05; Mon, 30 Jan 2023 11:24:16 +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: <20230130103343.GA11663@lst.de> References: <20230130103343.GA11663@lst.de> <20230130092157.1759539-21-hch@lst.de> <20230130092157.1759539-1-hch@lst.de> <3347459.1675074683@warthog.procyon.org.uk> To: Christoph Hellwig Cc: dhowells@redhat.com, linux-block@vger.kernel.org, ceph-devel@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-nvme@lists.infradead.org, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, kvm@vger.kernel.org, netdev@vger.kernel.org, linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org, devel@lists.orangefs.org, io-uring@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 20/23] rxrpc: use bvec_set_page to initialize a bvec MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <3351917.1675077855.1@warthog.procyon.org.uk> Date: Mon, 30 Jan 2023 11:24:15 +0000 Message-ID: <3351918.1675077855@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Christoph Hellwig wrote: > On Mon, Jan 30, 2023 at 10:31:23AM +0000, David Howells wrote: > > Christoph Hellwig wrote: > > > > > + bvec_set_page(&bv, ZERO_PAGE(0), len, 0); > > > > Maybe bvec_set_zero_page()? > > Why? Seems to be something people want to do quite a lot and don't know about. I've seen places where someone allocates a buffer and clears it just to use as a source of zeros. There's at least one place in cifs, for example. I know about it from wrangling arch code, but most people working on Linux haven't done that. David