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 X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4EAF2C43331 for ; Sun, 29 Mar 2020 03:00:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1E8D0206DB for ; Sun, 29 Mar 2020 03:00:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="nEBs34CU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727191AbgC2DAK (ORCPT ); Sat, 28 Mar 2020 23:00:10 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:58074 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726316AbgC2DAK (ORCPT ); Sat, 28 Mar 2020 23:00:10 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=tzQQI4sPYIQBmBbwCro/n16BP95THEmRO7t6mifRML4=; b=nEBs34CUPbdlvIX+D+1uQ1RH24 Ej5dOZ3lLrQuut9PtYNGkXA3koeQSQDdqMsYWaMEp38KgpDHYt8XQzVxIL0+LIbI71dtFlnqUNYUI +b8YfoGgqyK7V3Q2hkO5qRe9i9vorjXPJjM783KKCNLoKzNKArwYEbKteh5/DeRV/STBoJRPsqniL vyEcyBq095i2wwMZa3rKCvmt4CciHoEdoxVj9OjEF170WeNqffsvP+GXUqd9RDH5LkA9FKVqR4F1I VHwBcBcQA7Rtrf8fWswpp038xYh+MxshHzYqQ2kP4XDg9Gu+3InwGR63sWP94CEsMbluooRi8qUR0 HrUD8Z/g==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jIOAs-0002Hp-Jl; Sun, 29 Mar 2020 02:59:46 +0000 Date: Sat, 28 Mar 2020 19:59:46 -0700 From: Matthew Wilcox To: Alastair D'Silva Cc: "Aneesh Kumar K . V" , Oliver O'Halloran , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Frederic Barrat , Andrew Donnellan , Arnd Bergmann , Greg Kroah-Hartman , Dan Williams , Vishal Verma , Dave Jiang , Ira Weiny , Andrew Morton , Mauro Carvalho Chehab , "David S. Miller" , Rob Herring , Anton Blanchard , Krzysztof Kozlowski , Mahesh Salgaonkar , Madhavan Srinivasan , =?iso-8859-1?Q?C=E9dric?= Le Goater , Anju T Sudhakar , Hari Bathini , Thomas Gleixner , Greg Kurz , Nicholas Piggin , Masahiro Yamada , Alexey Kardashevskiy , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-nvdimm@lists.01.org, linux-mm@kvack.org Subject: Re: [PATCH v4 10/25] nvdimm: Add driver for OpenCAPI Persistent Memory Message-ID: <20200329025946.GU22483@bombadil.infradead.org> References: <20200327071202.2159885-1-alastair@d-silva.org> <20200327071202.2159885-11-alastair@d-silva.org> <20200329025617.GT22483@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200329025617.GT22483@bombadil.infradead.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Mar 28, 2020 at 07:56:17PM -0700, Matthew Wilcox wrote: > On Fri, Mar 27, 2020 at 06:11:47PM +1100, Alastair D'Silva wrote: > > +static struct mutex minors_idr_lock; > > +static struct idr minors_idr; > ... > > + mutex_lock(&minors_idr_lock); > > + minor = idr_alloc(&minors_idr, ocxlpmem, 0, NUM_MINORS, GFP_KERNEL); > > + mutex_unlock(&minors_idr_lock); > ... > > + mutex_lock(&minors_idr_lock); > > + idr_remove(&minors_idr, MINOR(ocxlpmem->dev.devt)); > > + mutex_unlock(&minors_idr_lock); > ... > > + mutex_init(&minors_idr_lock); > > + idr_init(&minors_idr); > > Unless you look up ocxlpmem by minor number later in the patch series (and > most of the series didn't make it to my mailbox), this can just be an ida. > > static DEFINE_IDA(minors); > ... > minor = ida_alloc_max(&minors, NUM_MINORS, GFP_KERNEL); Oops. NUM_MINORS - 1. Or #define MAX_MINOR 255 since you only seem to use NUM_MINORS in this one place. > ... > ida_free(&minors, MINOR(ocxlpmem->dev.devt)); > ... > and you can drop the dynamic initialisation. And the mutex.