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Mon, 5 Mar 2018 19:22:22 +0000 Received: from KL1P15301MB0006.APCP153.PROD.OUTLOOK.COM ([10.170.167.17]) by KL1P15301MB0006.APCP153.PROD.OUTLOOK.COM ([10.170.167.17]) with mapi id 15.20.0588.001; Mon, 5 Mar 2018 19:22:22 +0000 From: Dexuan Cui To: "bhelgaas@google.com" , "linux-pci@vger.kernel.org" , KY Srinivasan , Stephen Hemminger , "olaf@aepfle.de" , "apw@canonical.com" , "jasowang@redhat.com" CC: "linux-kernel@vger.kernel.org" , "driverdev-devel@linuxdriverproject.org" , Haiyang Zhang , "vkuznets@redhat.com" , "marcelo.cerri@canonical.com" , "Michael Kelley (EOSG)" , Dexuan Cui , Jack Morgenstein , "stable@vger.kernel.org" Subject: [PATCH v2 5/6] PCI: hv: hv_pci_devices_present(): only queue a new work when necessary Thread-Topic: [PATCH v2 5/6] PCI: hv: hv_pci_devices_present(): only queue a new work when necessary Thread-Index: AQHTtLdILulEelG7Ik+GDDlpqOy57A== Date: Mon, 5 Mar 2018 19:22:21 +0000 Message-ID: <20180305192134.32207-6-decui@microsoft.com> References: <20180305192134.32207-1-decui@microsoft.com> In-Reply-To: <20180305192134.32207-1-decui@microsoft.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-mailer: git-send-email 2.15.1 authentication-results: spf=none (sender IP is ) smtp.mailfrom=decui@microsoft.com; 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DIR:OUT; SFP:1102; SCL:1; SRVR:KL1P15301MB0039; H:KL1P15301MB0006.APCP153.PROD.OUTLOOK.COM; FPR:; SPF:None; PTR:InfoNoRecords; A:1; MX:1; LANG:en; received-spf: None (protection.outlook.com: microsoft.com does not designate permitted sender hosts) x-microsoft-antispam-message-info: KQ1ql4XAY+gW4MxI/c9CQL3dv7Ys7D5qhami4a7FK+pyNkJS8Rar8vUNddQSJYFi7fID6eqeanbuxsD5x6FUUVUsq+HJwcuSyYh4Bg8wALzltYlQ4iCxtD4LTocJ4XaifKOcikOYEikizLcoZK40xRwOjOfWVmFd0btMHv8qAGhakKVgpPhd6hafFPSJU6jy3dInIZqXtCPjZcyo15xqDllAIjHctiqws07saKHvTl7mfr3QL/TT7gpRlTG1ULYuKgrH6IY/6lP0whzUPpjd85yckMZneibFM3log+Y8fdZ91v4EIVnoc3CW5XyoSuwYBwpKG/jHY1gqmNZGgVUJ8Q== spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM MIME-Version: 1.0 X-OriginatorOrg: microsoft.com X-MS-Exchange-CrossTenant-Network-Message-Id: d50c2a34-c783-4c5f-2e25-08d582ce6bbd X-MS-Exchange-CrossTenant-originalarrivaltime: 05 Mar 2018 19:22:21.8992 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47 X-MS-Exchange-Transport-CrossTenantHeadersStamped: KL1P15301MB0039 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If there is a pending work, we just need to add the new dr into the dr_list. This is suggested by Michael Kelley. Signed-off-by: Dexuan Cui Cc: Vitaly Kuznetsov Cc: Jack Morgenstein Cc: stable@vger.kernel.org Cc: Stephen Hemminger Cc: K. Y. Srinivasan Cc: Michael Kelley (EOSG) --- drivers/pci/host/pci-hyperv.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c index 3a385212f666..d3aa6736a9bb 100644 --- a/drivers/pci/host/pci-hyperv.c +++ b/drivers/pci/host/pci-hyperv.c @@ -1733,6 +1733,7 @@ static void hv_pci_devices_present(struct hv_pcibus_device *hbus, struct hv_dr_state *dr; struct hv_dr_work *dr_wrk; unsigned long flags; + bool pending_dr; dr_wrk = kzalloc(sizeof(*dr_wrk), GFP_NOWAIT); if (!dr_wrk) @@ -1756,11 +1757,23 @@ static void hv_pci_devices_present(struct hv_pcibus_device *hbus, } spin_lock_irqsave(&hbus->device_list_lock, flags); + + /* + * If pending_dr is true, we have already queued a work, + * which will see the new dr. Otherwise, we need to + * queue a new work. + */ + pending_dr = !list_empty(&hbus->dr_list); list_add_tail(&dr->list_entry, &hbus->dr_list); - spin_unlock_irqrestore(&hbus->device_list_lock, flags); - get_hvpcibus(hbus); - queue_work(hbus->wq, &dr_wrk->wrk); + if (pending_dr) { + kfree(dr_wrk); + } else { + get_hvpcibus(hbus); + queue_work(hbus->wq, &dr_wrk->wrk); + } + + spin_unlock_irqrestore(&hbus->device_list_lock, flags); } /**