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Tue, 6 Mar 2018 18:21:55 +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; Tue, 6 Mar 2018 18:21:55 +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 v3 5/6] PCI: hv: hv_pci_devices_present(): only queue a new work when necessary Thread-Topic: [PATCH v3 5/6] PCI: hv: hv_pci_devices_present(): only queue a new work when necessary Thread-Index: AQHTtXgBUSAq7dV8DEe3C/6N5QPNyw== Date: Tue, 6 Mar 2018 18:21:55 +0000 Message-ID: <20180306182128.23281-6-decui@microsoft.com> References: <20180306182128.23281-1-decui@microsoft.com> In-Reply-To: <20180306182128.23281-1-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:KL1P15301MB0021; 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: zr+8NMmESl+2t7Ib5NPmLbs+7P8stW2Th7pU0a009pmgi+pZTMI1LmvcYdpQrDzSqPhHAsH0eZe3S72Tu2INSGqAKhffG8XvgoAJt39iK+xhbdWZFb5RQpb/K98zcuBc/XYQ9S7w48GgTt3hB/8XmlmK2ZGl8q53XsMHnmMSRwlskm2CtGc2Qj0SPnXcH60IP4k+j5z0Zd0+Aem3MXJ1+iF+cOpW27oouVuAadjP/MpZI0PhK7612qxPriy51nN3hOCVIYevDZlUszh1Adek4lKKcTw/hzP9oRtZNl5Vy16JWm6Jof6C2sdCK+PgiIN/BTXsXH8sshzakzmRCkKVjQ== spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM MIME-Version: 1.0 X-OriginatorOrg: microsoft.com X-MS-Exchange-CrossTenant-Network-Message-Id: 8d9546b5-13dd-476d-0fda-08d5838f245b X-MS-Exchange-CrossTenant-originalarrivaltime: 06 Mar 2018 18:21:55.1338 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47 X-MS-Exchange-Transport-CrossTenantHeadersStamped: KL1P15301MB0021 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) Reviewed-by: Michael Kelley Acked-by: Haiyang Zhang --- drivers/pci/host/pci-hyperv.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c index 3a385212f666..265ba11e53e2 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 +1757,21 @@ 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); + } } /**