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([2a01:e0a:280:24f0:9db0:474c:ff43:9f5c]) by smtp.gmail.com with ESMTPSA id d15-20020ac8544f000000b0041cf5ec8b75sm2720761qtq.96.2023.11.14.05.29.39 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 14 Nov 2023 05:29:43 -0800 (PST) Message-ID: <18c7eb32-a67b-412e-8d0d-9bdc98d0cbf8@redhat.com> Date: Tue, 14 Nov 2023 14:29:39 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 03/21] vfio/common: return early if space isn't empty Content-Language: en-US To: Zhenzhong Duan , qemu-devel@nongnu.org Cc: alex.williamson@redhat.com, jgg@nvidia.com, nicolinc@nvidia.com, joao.m.martins@oracle.com, eric.auger@redhat.com, peterx@redhat.com, jasowang@redhat.com, kevin.tian@intel.com, yi.l.liu@intel.com, yi.y.sun@intel.com, chao.p.peng@intel.com References: <20231114100955.1961974-1-zhenzhong.duan@intel.com> <20231114100955.1961974-4-zhenzhong.duan@intel.com> From: =?UTF-8?Q?C=C3=A9dric_Le_Goater?= In-Reply-To: <20231114100955.1961974-4-zhenzhong.duan@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=clg@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_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 11/14/23 11:09, Zhenzhong Duan wrote: > This is a trivial optimization. If there is active container in space, > vfio_reset_handler will never be unregistered. So revert the check of > space->containers and return early. > > Signed-off-by: Zhenzhong Duan Reviewed-by: Cédric Le Goater Thanks, C. > --- > hw/vfio/common.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/hw/vfio/common.c b/hw/vfio/common.c > index 572ae7c934..934f4f5446 100644 > --- a/hw/vfio/common.c > +++ b/hw/vfio/common.c > @@ -1462,10 +1462,13 @@ VFIOAddressSpace *vfio_get_address_space(AddressSpace *as) > > void vfio_put_address_space(VFIOAddressSpace *space) > { > - if (QLIST_EMPTY(&space->containers)) { > - QLIST_REMOVE(space, list); > - g_free(space); > + if (!QLIST_EMPTY(&space->containers)) { > + return; > } > + > + QLIST_REMOVE(space, list); > + g_free(space); > + > if (QLIST_EMPTY(&vfio_address_spaces)) { > qemu_unregister_reset(vfio_reset_handler, NULL); > }