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[174.89.135.171]) by smtp.gmail.com with ESMTPSA id af79cd13be357-7e67f72950csm1596171585a.65.2025.08.11.12.33.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Aug 2025 12:33:39 -0700 (PDT) Date: Mon, 11 Aug 2025 15:33:32 -0400 From: Peter Xu To: Paolo Bonzini Cc: qemu-devel@nongnu.org, imammedo@redhat.com, richard.henderson@linaro.org Subject: Re: [PATCH 3/8] accel: use atomic accesses for exit_request Message-ID: References: <20250808185905.62776-1-pbonzini@redhat.com> <20250808185905.62776-4-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20250808185905.62776-4-pbonzini@redhat.com> Received-SPF: pass client-ip=170.10.129.124; envelope-from=peterx@redhat.com; helo=us-smtp-delivery-124.mimecast.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, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Fri, Aug 08, 2025 at 08:59:00PM +0200, Paolo Bonzini wrote: > CPU threads write exit_request as a "note to self" that they need to > go out to a slow path. This write happens out of the BQL and can be > a data race with another threads' cpu_exit(); use atomic accesses > consistently. > > Signed-off-by: Paolo Bonzini Reviewed-by: Peter Xu -- Peter Xu