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CTRY:IE; LANG:en; SCL:1; SRV:; IPV:CAL; SFV:NSPM; H:64aa7808-outbound-1.mta.getcheckrecipient.com; PTR:ec2-63-35-35-123.eu-west-1.compute.amazonaws.com; CAT:NONE; SFS:(4636009)(376002)(39860400002)(136003)(346002)(396003)(36840700001)(46966006)(36756003)(82310400003)(82740400003)(33656002)(8936002)(4326008)(86362001)(26005)(5660300002)(44832011)(1076003)(2616005)(956004)(478600001)(8676002)(83380400001)(336012)(2906002)(81166007)(36860700001)(186003)(6862004)(53546011)(316002)(356005)(8886007)(7696005)(16526019)(70586007)(55016002)(47076005)(70206006); DIR:OUT; SFP:1101; X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 16 Apr 2021 09:13:10.0290 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: a86eb1b9-a19d-4e24-bc32-08d900b7dae5 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: AM5EUR03FT025.eop-EUR03.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR08MB3535 X-Spam-Status: No, score=-7.8 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, MSGID_FROM_MTA_HEADER, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_PASS, SPF_PASS, TXREP, UNPARSEABLE_RELAY autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) 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: Fri, 16 Apr 2021 09:13:25 -0000 The 04/15/2021 15:21, Adhemerval Zanella wrote: > On 13/04/2021 05:19, Szabolcs Nagy via Libc-alpha wrote: > > This is a follow up patch to the fix for bug 19329. This adds > > relaxed MO atomics to accesses that are racy, but relaxed MO is > > enough. > > Could you extend a bit why relaxed MO should be suffice? is it ok to change the commit message to: This is a follow up patch to the fix for bug 19329. This adds relaxed MO atomics to accesses that are racy, but relaxed MO is enough. The racy accesses all follow the pattern that the write is behind the dlopen lock, but a read can happen concurrently (e.g. during tls access) without holding the lock. For slotinfo entries the read value only matters if it reads from a synchronized write in dlopen or dlclose, otherwise the related dtv entry is not valid to access so it is fine to leave it in inconsistent state. Same for GL(dl_tls_max_dtv_idx) and GL(dl_tls_generation), but there we rely on the read value being larger than the last written value that was synchronized. > > Patch looks good, just a small request below. > > Reviewed-by: Adhemerval Zanella thanks.