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Cota" To: Peter Maydell Subject: Re: [PATCH 18/19] target/arm: Fix tsan warning in cpu.c Message-ID: <20200523171814.GA382220@sff> References: <20200522160755.886-1-robert.foley@linaro.org> <20200522160755.886-19-robert.foley@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Received-SPF: softfail client-ip=2607:f8b0:4864:20::743; envelope-from=cota@braap.org; helo=mail-qk1-x743.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -11 X-Spam_score: -1.2 X-Spam_bar: - X-Spam_report: (-1.2 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_SOFTFAIL=0.665, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN 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: Peter Puhov , Richard Henderson , Alex =?iso-8859-1?Q?Benn=E9e?= , Robert Foley , QEMU Developers Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, May 22, 2020 at 23:36:18 +0100, Peter Maydell wrote: > So is this: > (a) a TSan false positive, because we've analysed the use > of this struct field and know it's not a race because > [details], but which we're choosing to silence in this way > (b) an actual race for which the correct fix is to make the > accesses atomic because [details] > > ? It is (b), as shown in the per-cpu lock series. In particular, see these two patches: - [PATCH v9 33/74] cpu: define cpu_interrupt_request helpers https://lists.nongnu.org/archive/html/qemu-devel/2020-05/msg06322.html - [PATCH v9 39/74] arm: convert to cpu_interrupt_request https://lists.nongnu.org/archive/html/qemu-devel/2020-05/msg06328.html Since a more thorough fix is included in that other series, I think this patch should be dropped from this series -- I'll post a reply to patch 00/19 with more details. Thanks, Emilio