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=-11.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 D13B2C433E0 for ; Tue, 19 May 2020 13:10:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9A5D7206C3 for ; Tue, 19 May 2020 13:10:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="h5BqlN/+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728894AbgESNKO (ORCPT ); Tue, 19 May 2020 09:10:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44254 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727057AbgESNKO (ORCPT ); Tue, 19 May 2020 09:10:14 -0400 Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1C255C08C5C0 for ; Tue, 19 May 2020 06:10:14 -0700 (PDT) Received: by mail-pl1-x641.google.com with SMTP id m7so5609622plt.5 for ; Tue, 19 May 2020 06:10:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=/t5Q76brEmiFOkE+Fa8TY6sSlQLt/nYO/w8O35DojmA=; b=h5BqlN/+Hn9SGQ7i05BQI6KcD+y4PK5BC4LW9aaiaupa6G3aE45naOipKdwg6RCH+z B1aROfQf/swVtAmV9Q3WeWZ6cxIsb+NILK6oCN+zT/pcV6GNvbUxUZShW7odj65ms9R+ xIHvXzL8IXOcwWQWXRWasRMqYVHG+zpsWktfOzu/vaVlJ6dY+5GV5WqPfDhIKy3bmBMI IxR34xfF9zHeKIsmCn0KXpRlOJNbyyejvuM01J+4gWx251icBsDDdvF5y1PkMqlTyBzq k1114wNiX4ZBbXhPocM00mrka6IDLFqrh7hNym8mGF/Qh3XdmakcA4euR3EnadEZskH9 rTpQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=/t5Q76brEmiFOkE+Fa8TY6sSlQLt/nYO/w8O35DojmA=; b=P9tvTuASbJOCs8oZ1eGuGjSzPKMOIQ83z9lF1MTKjL3Wg1mM8vSw4DG7S2gQH7etXw zxyhV+bagjcumA6ZkATD3XZhGRdkY5VcmDKtnsPu6uqqeETNxGHl6RXw4ciKIxacllqN WDeiTQWAZhoG9UnpVLGTakyk98fSkrLDLEeY8e03/epYYhdU+wej/3yHDBFDXFApM2GT Mdwf30VJg0NzyxJ3Anqg+9kAGSrUHu4yutMd/kaG1ffgmFC6ehsk/pWUBEt5b/PNEiFq CFPc+4hIEpuDqL3zG0a3T/VjfYbrShOL0qcO7n6Q7fIaDCg3yLSEU/mG/KIYkltj8PO8 YJUQ== X-Gm-Message-State: AOAM533VtoLduiHUZL6SnGe1WYRUP1ho54SMGmDcevTlTtLoS19BhtJp wGkT32/PasP9SRquQU6Xk7mdAw== X-Google-Smtp-Source: ABdhPJyRXNx07N2fTf9QLSdqn0WHYd/NSH1ZR/mcHjoNMJ6OQpXvCcLfl4Fg32pYTm7gQbAm2QJ0Sg== X-Received: by 2002:a17:902:d693:: with SMTP id v19mr15203765ply.288.1589893813434; Tue, 19 May 2020 06:10:13 -0700 (PDT) Received: from google.com ([2620:15c:2cd:202:2523:d194:de3b:636f]) by smtp.gmail.com with ESMTPSA id 7sm8757569pfc.203.2020.05.19.06.10.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 19 May 2020 06:10:11 -0700 (PDT) Date: Tue, 19 May 2020 06:10:09 -0700 From: Michel Lespinasse To: Laurent Dufour Cc: Matthew Wilcox , Andrew Morton , linux-mm , LKML , Peter Zijlstra , Vlastimil Babka , Liam Howlett , Jerome Glisse , Davidlohr Bueso , David Rientjes , Hugh Dickins , Ying Han , Jason Gunthorpe , Daniel Jordan Subject: Re: [PATCH v5.5 10/10] mmap locking API: rename mmap_sem to mmap_lock Message-ID: <20200519131009.GD189720@google.com> References: <20200422001422.232330-1-walken@google.com> <20200422001422.232330-11-walken@google.com> <20200422015829.GR5820@bombadil.infradead.org> <20200423015917.GA13910@bombadil.infradead.org> <20200424012612.GA158937@google.com> <20200424013958.GC158937@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 18, 2020 at 03:45:22PM +0200, Laurent Dufour wrote: > Le 24/04/2020 à 03:39, Michel Lespinasse a écrit : > > Rename the mmap_sem field to mmap_lock. Any new uses of this lock > > should now go through the new mmap locking api. The mmap_lock is > > still implemented as a rwsem, though this could change in the future. > > > > diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c > > index dc9ef302f517..701f3995f621 100644 > > --- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c > > +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c > > @@ -661,7 +661,7 @@ static int etnaviv_gem_userptr_get_pages(struct etnaviv_gem_object *etnaviv_obj) > > struct etnaviv_gem_userptr *userptr = &etnaviv_obj->userptr; > > int ret, pinned = 0, npages = etnaviv_obj->base.size >> PAGE_SHIFT; > > - might_lock_read(¤t->mm->mmap_sem); > > + might_lock_read(¤t->mm->mmap_lock); > > Why not a mm_might_lock_read() new API to hide the mmap_lock, and add it to > the previous patch? I'm not sure why this is needed - we may rework the lock to be something else than rwsem, but might_lock_read should still apply to it and make sense ? I'm not sure what the extra API would bring... -- Michel "Walken" Lespinasse A program is never fully debugged until the last user dies.