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Lu" , Adhemerval Zanella Netto CC: Noah Goldstein , GNU C Library Subject: Re: [PATCH 3/7] Remove atomic_bit_set/bit_test_set Thread-Topic: [PATCH 3/7] Remove atomic_bit_set/bit_test_set Thread-Index: AQHYkUrot9wGWG5wTUWQh2iJcYWu/K1xhEEAgAAktgCAAAJyx4AAC0YAgAACwLiAAAegAIAAAVoAgAAApNOAAAjWgIAABy0AgAk5RYCAAAYagIAABgd5 Date: Tue, 12 Jul 2022 18:44:27 +0000 Message-ID: References: <0f40a803-eb51-e803-edd3-e6cf05a97b74@linaro.org> In-Reply-To: Accept-Language: en-GB, en-US Content-Language: en-GB X-MS-Has-Attach: X-MS-TNEF-Correlator: msip_labels: Authentication-Results-Original: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=arm.com; X-MS-Office365-Filtering-Correlation-Id: 2a664d8d-9ba8-423d-0e0d-08da6436980a x-ms-traffictypediagnostic: HE1PR0801MB1771:EE_|VE1EUR03FT004:EE_|AM6PR08MB4915:EE_ x-checkrecipientrouted: true nodisclaimer: true X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam-Untrusted: BCL:0; X-Microsoft-Antispam-Message-Info-Original: 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 X-Forefront-Antispam-Report-Untrusted: CIP:255.255.255.255; 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PTR:ec2-63-35-35-123.eu-west-1.compute.amazonaws.com; CAT:NONE; SFS:(13230016)(4636009)(136003)(39860400002)(396003)(346002)(376002)(40470700004)(36840700001)(46966006)(81166007)(110136005)(186003)(6506007)(82740400003)(478600001)(86362001)(26005)(70586007)(47076005)(54906003)(7696005)(70206006)(316002)(8676002)(4326008)(33656002)(9686003)(8936002)(40460700003)(52536014)(55016003)(4744005)(336012)(40480700001)(2906002)(5660300002)(83380400001)(82310400005)(36860700001)(356005)(41300700001); DIR:OUT; SFP:1101; X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Jul 2022 18:44:46.7060 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 2a664d8d-9ba8-423d-0e0d-08da6436980a X-MS-Exchange-CrossTenant-Id: f34e5979-57d9-4aaa-ad4d-b122a662184d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=f34e5979-57d9-4aaa-ad4d-b122a662184d; Ip=[63.35.35.123]; Helo=[64aa7808-outbound-1.mta.getcheckrecipient.com] X-MS-Exchange-CrossTenant-AuthSource: VE1EUR03FT004.eop-EUR03.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM6PR08MB4915 X-Spam-Status: No, score=-5.2 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, FORGED_SPF_HELO, KAM_DMARC_NONE, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_PASS, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE, UNPARSEABLE_RELAY autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 12 Jul 2022 18:44:53 -0000 Hi,=0A= =0A= I don't believe it could make a difference since it isn't performance criti= cal=A0code.=0A= Note that several similar fetch_or/fetch_and=A0are used which do not=A0opti= mize=A0into a=0A= bitset operation, so even if we fix this particular case to use unsigned, t= here are many=0A= others. IIRC there is even a fetch_or with zero which is kind of useless!= =0A= =0A= More importantly, it raises a question for locking: we currently use a comp= are-exchange=0A= for each lock and unlock. If compare-exchange has higher overheads than oth= er atomics=0A= then we should investigate more efficient locking sequences.=0A= =0A= Cheers,=0A= Wilco=