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=-11.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 A1F8FC433E0 for ; Tue, 16 Mar 2021 16:14:31 +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 30040650F8 for ; Tue, 16 Mar 2021 16:14:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 30040650F8 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]:34670 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lMCL0-0004VY-8l for qemu-devel@archiver.kernel.org; Tue, 16 Mar 2021 12:14:30 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:36110) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lMC7B-0000tu-Oc; Tue, 16 Mar 2021 12:00:20 -0400 Received: from mail-wr1-x42e.google.com ([2a00:1450:4864:20::42e]:45167) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lMC79-0000HD-AC; Tue, 16 Mar 2021 12:00:12 -0400 Received: by mail-wr1-x42e.google.com with SMTP id e10so10732746wro.12; Tue, 16 Mar 2021 09:00:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=itrz6CLd3fj2mHEdKB1Eeo/F30NCpLTRd9Ue0cOohR4=; b=Og5r8suKg1G4959uDIV2L+mpSPhz6qPO36l2EdXYFX7EYZnnpHJBvWnFCjE0msjdQo vrJ5kqeaOYpFL1P4trG3KDMmSFTOINw3E1lSB31fL+36zI7rHQAcNUXooGm4Dh6O/pLi fsYmYdIsY0+1DP3Q+88ek29hs6KnLoT3XMNxOlYZyWNnE5AKtBzHskgVfILMlCVvaWQ3 VKk/MfPvFTjBNxCubM8fjueN9DnPZ7YbQroP4wm9mvk82ilMM1Gp2PPVuG9BZiisWGVy 4P+1L0UMPU0Xuuo7vKcExzvKo2YwvJKeBvr/+JgGWujo9ZNXkKPlLwbo+iJupEDgKC7T CNGQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :mime-version:content-transfer-encoding; bh=itrz6CLd3fj2mHEdKB1Eeo/F30NCpLTRd9Ue0cOohR4=; b=EEVvCs9DbwXzNdXvjHSv1tUyVq8MMYo6m0U908Oofn8YF72zcGSUxSg9ixd/Ivejmw WVIS5cdm8XMMN7vxDN1Jpq4ArIGYlu8TPI666LkLhKCDQytckmm+qQZDWOtZ24BTs2t4 VALrrJoGbiE7URE6FSjS+cmDSRkaQl5dZr2cq5AhPKgeAMF8BnmVnjdKqoSApGp+f0ke MMgfQaoeCNYKZUk8cRt4Qt/fkqwLPnZjSMynxOF8lzgiDT97tVlhdVwFARTPHeUpQXkV 8gsBEUFeHDswQXng3HpNNKSd0zYvegy7U2FQMXZCwOSkvSfFk7iRZbeds+5+ckZFgmJX NOww== X-Gm-Message-State: AOAM533aIWE+LPFzzlk3WkMaeXrzB667HcDXLDWm4deMI/mF8k/YAkjB H83oGj/LSa53gE11xZdNhW9xoDV9Lds= X-Google-Smtp-Source: ABdhPJz9KfOQdAiA4I+Nq4GYg2waay9lHSTR7JV//9Zv5bdJIldDpmBXkxSLM+svDdlunibzPkTHxw== X-Received: by 2002:a5d:4312:: with SMTP id h18mr5667387wrq.193.1615910408965; Tue, 16 Mar 2021 09:00:08 -0700 (PDT) Received: from avogadro.lan ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id j14sm22674851wrw.69.2021.03.16.09.00.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Mar 2021 09:00:08 -0700 (PDT) From: Paolo Bonzini To: qemu-devel@nongnu.org Subject: [PATCH v3 0/5] coroutine rwlock downgrade fix, minor VDI changes Date: Tue, 16 Mar 2021 17:00:02 +0100 Message-Id: <20210316160007.135459-1-pbonzini@redhat.com> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=2a00:1450:4864:20::42e; envelope-from=paolo.bonzini@gmail.com; helo=mail-wr1-x42e.google.com X-Spam_score_int: -14 X-Spam_score: -1.5 X-Spam_bar: - X-Spam_report: (-1.5 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FORGED_FROMDOMAIN=0.249, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.25, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no 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: david.edmondson@oracle.com, kwolf@redhat.com, qemu-block@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This is a resubmit of David Edmondson's series at https://patchew.org/QEMU/20210309144015.557477-1-david.edmondson@oracle.com/. After closer analysis on IRC, the CoRwLock's attempt to ensure fairness turned out to be flawed. Therefore, this series reimplements CoRwLock without using a CoQueue. Tracking whether each queued coroutine is a reader/writer makes it possible to never wake a writer when only readers should be allowed and vice versa. David Edmondson (4): block/vdi: When writing new bmap entry fails, don't leak the buffer block/vdi: Don't assume that blocks are larger than VdiHeader coroutine/mutex: Store the coroutine in the CoWaitRecord only once test-coroutine: Add rwlock downgrade test Paolo Bonzini (1): coroutine-lock: reimplement CoRwLock to fix downgrade bug block/vdi.c | 11 ++- include/qemu/coroutine.h | 10 ++- tests/unit/test-coroutine.c | 112 ++++++++++++++++++++++++++ util/qemu-coroutine-lock.c | 151 +++++++++++++++++++++++------------- 4 files changed, 225 insertions(+), 59 deletions(-) -- 2.29.2