From patchwork Fri Nov 22 08:49:23 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Huth X-Patchwork-Id: 13882887 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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id D810CE65D34 for ; Fri, 22 Nov 2024 08:50:32 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tEPMC-0007kx-KL; Fri, 22 Nov 2024 03:49:40 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tEPMB-0007kp-Lk for qemu-devel@nongnu.org; Fri, 22 Nov 2024 03:49:39 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tEPMA-0003FA-37 for qemu-devel@nongnu.org; Fri, 22 Nov 2024 03:49:39 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1732265377; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=KNZQI7ylQIOE/iFKodvgac7pAsGuEdA32WTqOV4P8pA=; b=dSnVKCdOVv+aYt8tuCUbMzLJgKKcx1SRV5kLke2go3NWC7LvNsTtPRy+WrpkSi1vEMbb6E lKUnXUiSmDHuN9Yt8Y3O0sp1hHi704t8e4yP9ymriUqewCn5T9nChZlOVNi2KcM6bwvU5D xh6pr6by+98l1XiPTpjk++52Y/6h4kk= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-474-DhqWTc0dM3CMu00N60iOKA-1; Fri, 22 Nov 2024 03:49:31 -0500 X-MC-Unique: DhqWTc0dM3CMu00N60iOKA-1 X-Mimecast-MFC-AGG-ID: DhqWTc0dM3CMu00N60iOKA Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (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 mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id ED5481955BEF; Fri, 22 Nov 2024 08:49:28 +0000 (UTC) Received: from thuth-p1g4.str.redhat.com (dhcp-192-206.str.redhat.com [10.33.192.206]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 7AA161956086; Fri, 22 Nov 2024 08:49:24 +0000 (UTC) From: Thomas Huth To: qemu-devel@nongnu.org Cc: qemu-trivial@nongnu.org, Eduardo Habkost , Marcel Apfelbaum , =?utf-8?q?Philippe_Mathieu-D?= =?utf-8?q?aud=C3=A9?= , Yanan Wang , Zhao Liu Subject: [RFC PATCH for-10.0] include/hw/boards: Optimize the booleans in MachineClass Date: Fri, 22 Nov 2024 09:49:23 +0100 Message-ID: <20241122084923.1542743-1-thuth@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 Received-SPF: pass client-ip=170.10.133.124; envelope-from=thuth@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.14, 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_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org While looking at the QEMU binary with "pahole", I noticed that we could optimize the size of MachineClass a little bit: So far we are using a mixture of a bitfield and single "bool" members here for the boolean flags. Declaring all flags as part of the bitfield helps to shrink the size of the struct a little bit. Signed-off-by: Thomas Huth --- It's just a micro-optimization (the size of the struct decreases by eight bytes), so I'm not sure whether it's worth the effort...? include/hw/boards.h | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/include/hw/boards.h b/include/hw/boards.h index 36fbb9b59d..c6946bd319 100644 --- a/include/hw/boards.h +++ b/include/hw/boards.h @@ -285,8 +285,16 @@ struct MachineClass { no_cdrom:1, no_sdcard:1, pci_allow_0_address:1, - legacy_fw_cfg_order:1; - bool is_default; + legacy_fw_cfg_order:1, + is_default:1, + auto_enable_numa_with_memhp:1, + auto_enable_numa_with_memdev:1, + ignore_boot_device_suffixes:1, + smbus_no_migration_support:1, + nvdimm_supported:1, + numa_mem_supported:1, + auto_enable_numa:1, + cpu_cluster_has_numa_boundary:1; const char *default_machine_opts; const char *default_boot_order; const char *default_display; @@ -304,14 +312,6 @@ struct MachineClass { int numa_mem_align_shift; const char * const *valid_cpu_types; strList *allowed_dynamic_sysbus_devices; - bool auto_enable_numa_with_memhp; - bool auto_enable_numa_with_memdev; - bool ignore_boot_device_suffixes; - bool smbus_no_migration_support; - bool nvdimm_supported; - bool numa_mem_supported; - bool auto_enable_numa; - bool cpu_cluster_has_numa_boundary; SMPCompatProps smp_props; const char *default_ram_id;