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[213.106.181.179]) by smtp.gmail.com with ESMTPSA id v22-20020a7bcb56000000b003fbb9339b29sm8846384wmj.42.2023.07.22.14.44.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 22 Jul 2023 14:44:23 -0700 (PDT) From: Richard Henderson To: qemu-devel@nongnu.org Cc: peter.maydell@linaro.org Subject: [PATCH v2 0/4] util/interval-tree: Avoid race conditions without optimization Date: Sat, 22 Jul 2023 22:44:18 +0100 Message-Id: <20230722214422.118743-1-richard.henderson@linaro.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Received-SPF: pass client-ip=2a00:1450:4864:20::333; envelope-from=richard.henderson@linaro.org; helo=mail-wm1-x333.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Read the left and right trees once, so that the gating tests are meaningful. This was only a problem at -O0, where the compiler didn't CSE the two reads. Changes for v2: * Use qatomic_read for left/right while searching (pmm) * Use qatomic_set_mb when inserting a new node, so that we're sure that the new node is consistent. * Abundance of caution: Use qatomic_read/set for manipulating parent. r~ Richard Henderson (4): util/interval-tree: Use qatomic_read for left/right while searching util/interval-tree: Use qatomic_set_mb in rb_link_node util/interval-tree: Introduce pc_parent util/interval-tree: Use qatomic_read/set for rb_parent_color util/interval-tree.c | 79 +++++++++++++++++++++++++++----------------- 1 file changed, 48 insertions(+), 31 deletions(-)