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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 BE4E8C433E0 for ; Thu, 4 Jun 2020 16:24:01 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 86DAB2053B for ; Thu, 4 Jun 2020 16:24:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="KNN/rzAF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 86DAB2053B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:39446 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jgseu-0002cV-PE for qemu-devel@archiver.kernel.org; Thu, 04 Jun 2020 12:24:00 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51598) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jgsdh-0001DN-Uo for qemu-devel@nongnu.org; Thu, 04 Jun 2020 12:22:45 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:45314 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jgsdf-0007fd-SG for qemu-devel@nongnu.org; Thu, 04 Jun 2020 12:22:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591287762; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=bkaBPgmzr0lMeHWUMJ62vNGfJWQwC8Xb5vQegkVuEtw=; b=KNN/rzAFTD86yGJR8ubIsYWlZcKcPPv8SUQBeQvsSzLy0Op2zpl7IFdDjKnIpHUWaI2CQQ N4wMWwCvDaDVRqk6cpiGg08QT97CeQfyMhj7LMgpGgonIb0oCW3Qma4JtoVwMMC6OpGvYh EPdOr3aE26B7s3cLgICNR5AkTRQO3P8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-280-CTZPl-nEOxycqWmNfUDJDg-1; Thu, 04 Jun 2020 12:22:35 -0400 X-MC-Unique: CTZPl-nEOxycqWmNfUDJDg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BC3A51005510; Thu, 4 Jun 2020 16:22:29 +0000 (UTC) Received: from [10.3.113.22] (ovpn-113-22.phx2.redhat.com [10.3.113.22]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3D27C60C47; Thu, 4 Jun 2020 16:22:29 +0000 (UTC) Subject: Re: [PATCH 1/2] lockable: use QLNULL for a null lockable To: Joe Slater , qemu-devel@nongnu.org References: <20200603224903.26268-1-joe.slater@windriver.com> <20200603224903.26268-2-joe.slater@windriver.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: Date: Thu, 4 Jun 2020 11:22:28 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200603224903.26268-2-joe.slater@windriver.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=205.139.110.61; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/04 01:08:38 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-trivial@nongnu.org, qemu-stable@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 6/3/20 5:49 PM, Joe Slater wrote: > Allows us to build with -Og and optimizations that > do not clean up dead-code. > > Signed-off-by: Joe Slater > > to be squished > > Signed-off-by: Joe Slater These last two lines can be elided (looks like a rebase mishap). > --- > block/block-backend.c | 4 ++-- > block/block-copy.c | 2 +- > block/mirror.c | 5 +++-- > fsdev/qemu-fsdev-throttle.c | 6 +++--- > hw/9pfs/9p.c | 2 +- > include/qemu/lockable.h | 3 +++ > util/qemu-co-shared-resource.c | 2 +- > 7 files changed, 14 insertions(+), 10 deletions(-) > If you use scripts/git.orderfile, your diff would show with the .h changes first, which are arguably the meat of this patch. > +++ b/block/mirror.c > @@ -28,6 +28,7 @@ > #define MAX_IO_BYTES (1 << 20) /* 1 Mb */ > #define DEFAULT_MIRROR_BUF_SIZE (MAX_IN_FLIGHT * MAX_IO_BYTES) > > + > /* The mirroring buffer is a list of granularity-sized chunks. > * Free chunks are organized in a list. > */ This hunk looks spurious. > +++ b/include/qemu/lockable.h > @@ -24,6 +24,9 @@ struct QemuLockable { > QemuLockUnlockFunc *unlock; > }; > > +#define QLNULL ((QemuLockable *)0) Why not ((QemuLocakable *)NULL) ? Why no comments why this type-safe NULL is useful? > + > + > /* This function gives an error if an invalid, non-NULL pointer type is passed > * to QEMU_MAKE_LOCKABLE. For optimized builds, we can rely on dead-code elimination > * from the compiler, and give the errors already at link time. > diff --git a/util/qemu-co-shared-resource.c b/util/qemu-co-shared-resource.c > index 1c83cd9..7423ea4 100644 > --- a/util/qemu-co-shared-resource.c > +++ b/util/qemu-co-shared-resource.c > @@ -64,7 +64,7 @@ void coroutine_fn co_get_from_shres(SharedResource *s, uint64_t n) > { > assert(n <= s->total); > while (!co_try_get_from_shres(s, n)) { > - qemu_co_queue_wait(&s->queue, NULL); > + qemu_co_queue_wait(&s->queue, QLNULL); It looks like your macro is added to give the compiler some type-safety, but it is not obvious how it matters from just the commit message, without also looking at patch 2/2. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org