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[70.30.145.63]) by smtp.gmail.com with ESMTPSA id t8-20020ac85888000000b003bb8c60cdf1sm1558142qta.78.2023.02.25.08.31.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 25 Feb 2023 08:31:49 -0800 (PST) From: Peter Xu To: qemu-devel@nongnu.org Cc: Maxim Levitsky , Stefan Hajnoczi , Juan Quintela , Paolo Bonzini , David Hildenbrand , "Dr . David Alan Gilbert" , Chuang Xu , =?utf-8?q?Philippe_Mathieu-Daud?= =?utf-8?q?=C3=A9?= , peterx@redhat.com Subject: [PATCH RFC 2/4] memory: Use rcu list variance for address_spaces modifications Date: Sat, 25 Feb 2023 11:31:39 -0500 Message-Id: <20230225163141.1209368-3-peterx@redhat.com> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230225163141.1209368-1-peterx@redhat.com> References: <20230225163141.1209368-1-peterx@redhat.com> MIME-Version: 1.0 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, DKIMWL_WL_HIGH=-0.001, 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_H2=-0.001, SPF_HELO_NONE=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 AddressSpace should be safe to RCU since it's released with call_rcu. Change the list insert/removal to use RCU variances. Signed-off-by: Peter Xu --- softmmu/memory.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/softmmu/memory.c b/softmmu/memory.c index a63e0bcbb7..c48e9cc6ed 100644 --- a/softmmu/memory.c +++ b/softmmu/memory.c @@ -3079,7 +3079,7 @@ void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name) as->ioeventfd_nb = 0; as->ioeventfds = NULL; QTAILQ_INIT(&as->listeners); - QTAILQ_INSERT_TAIL(&address_spaces, as, address_spaces_link); + QTAILQ_INSERT_TAIL_RCU(&address_spaces, as, address_spaces_link); as->name = g_strdup(name ? name : "anonymous"); address_space_update_topology(as); address_space_update_ioeventfds(as); @@ -3103,7 +3103,7 @@ void address_space_destroy(AddressSpace *as) memory_region_transaction_begin(); as->root = NULL; memory_region_transaction_commit(); - QTAILQ_REMOVE(&address_spaces, as, address_spaces_link); + QTAILQ_REMOVE_RCU(&address_spaces, as, address_spaces_link); /* At this point, as->dispatch and as->current_map are dummy * entries that the guest should never use. Wait for the old