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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 1693BC433ED for ; Tue, 6 Apr 2021 22:22:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DAA30613A7 for ; Tue, 6 Apr 2021 22:22:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344072AbhDFWWH (ORCPT ); Tue, 6 Apr 2021 18:22:07 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:54919 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232505AbhDFWWE (ORCPT ); Tue, 6 Apr 2021 18:22:04 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617747715; 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=s1hRxpt2ffdYHYrIGfbgGHgTPYMM56n8tQe3ShKBMhM=; b=AJ+AeVLoePuDTcePnkoTes1awG5sR1VHahTF89miIwWxkfw0p/BiT4DQlAP3/CkUs+2nR9 bOuBv6RI4jy2lxWesW19eOavb3/dpfSiXxt35IpPYv6pFzX8j/VC6Bgn3AdE9298tOa1sE xmq3xturfgt9wo+3op44N7R58isDX/Q= Received: from mail-oi1-f198.google.com (mail-oi1-f198.google.com [209.85.167.198]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-583-hqFsYXnvOUaQ30QAbLTabA-1; Tue, 06 Apr 2021 18:21:47 -0400 X-MC-Unique: hqFsYXnvOUaQ30QAbLTabA-1 Received: by mail-oi1-f198.google.com with SMTP id t186so5832710oih.1 for ; Tue, 06 Apr 2021 15:21:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=s1hRxpt2ffdYHYrIGfbgGHgTPYMM56n8tQe3ShKBMhM=; b=gTnzQ9NP3f94kCAKIf+YYv2oly0yXzDvC/J3t/rqpHDP8761b2Q0uG8oOOYkzsA6ig aQkae1Ci/Oqf4C/61HJ+8LU8bHbqmLE9BoUDO2Msn0LJUIxDHm37BMCNnY1bu8nDrrkH ujNZG0PMoYtQlya8HITp4iPuYE2i0cIx/ICj59OE6k8vzxGOpi/nG/lX4kFVXIqA+Ovc XIOOzUxUkyDXepCl1b9CLBqk2v/+H7eWKwFwWKxtQR8auaqVQP5RAr2l/X9wr3YzwQQS qOmZxtzFZ2hOb5a0kcW+BkoCkUPKrqkalCNc6hnuexOZf+v6h69/TAQMfeb+D9+vn50a EJcA== X-Gm-Message-State: AOAM531mYEziI5zOek0SMWwG8Xp08YQxAfbRYPY7orC26Kxoq199Eeli u6h+of3+ZPJANA33MrRYugtue3PiBa3KNAlP2ZRVAwxqk0CAykJCMxpleaSrHDBOmvE6HLz+Wk6 cgkVUAdX6n+6ZsZuo3P7Ylf67 X-Received: by 2002:a9d:303:: with SMTP id 3mr256743otv.268.1617747706954; Tue, 06 Apr 2021 15:21:46 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzVK/wKfco2rpUqiiNbYfzLUjvxyjVjuDGeQW5Ynxv/fOZ5VQFgqpDYynoPDmgw+xuTSyAjag== X-Received: by 2002:a9d:303:: with SMTP id 3mr256729otv.268.1617747706791; Tue, 06 Apr 2021 15:21:46 -0700 (PDT) Received: from halaneylaptop.redhat.com ([136.33.225.96]) by smtp.gmail.com with ESMTPSA id y10sm4854599oto.18.2021.04.06.15.21.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 06 Apr 2021 15:21:46 -0700 (PDT) From: Andrew Halaney To: bigeasy@linutronix.de Cc: linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org, Andrew Halaney , Chunyu Hu Subject: [RT PATCH] locking/rwsem-rt: Remove might_sleep() in __up_read() Date: Tue, 6 Apr 2021 17:19:52 -0500 Message-Id: <20210406221952.50399-1-ahalaney@redhat.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There's no chance of sleeping here, the reader is giving up the lock and possibly waking up the writer who is waiting on it. Reported-by: Chunyu Hu Signed-off-by: Andrew Halaney --- Hello, I ran into a warning caused by this, and I think the warning is incorrect. Please let me know if I'm wrong! I'm working off of linux-5.12.y-rt, but this applies cleanly to older stable branches as well. Thanks, Andrew kernel/locking/rwsem-rt.c | 1 - 1 file changed, 1 deletion(-) diff --git a/kernel/locking/rwsem-rt.c b/kernel/locking/rwsem-rt.c index 274172d5bb3a..b61edc4dcb73 100644 --- a/kernel/locking/rwsem-rt.c +++ b/kernel/locking/rwsem-rt.c @@ -198,7 +198,6 @@ void __up_read(struct rw_semaphore *sem) if (!atomic_dec_and_test(&sem->readers)) return; - might_sleep(); raw_spin_lock_irq(&m->wait_lock); /* * Wake the writer, i.e. the rtmutex owner. It might release the -- 2.30.2