From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966074AbdEOUgV (ORCPT ); Mon, 15 May 2017 16:36:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:58536 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966036AbdEOUgO (ORCPT ); Mon, 15 May 2017 16:36:14 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C805C239B0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=sstabellini@kernel.org From: Stefano Stabellini To: xen-devel@lists.xen.org Cc: linux-kernel@vger.kernel.org, sstabellini@kernel.org, jgross@suse.com, boris.ostrovsky@oracle.com, Stefano Stabellini Subject: [PATCH 03/18] xen/pvcalls: initialize the module and register the xenbus backend Date: Mon, 15 May 2017 13:35:55 -0700 Message-Id: <1494880570-14209-3-git-send-email-sstabellini@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1494880570-14209-1-git-send-email-sstabellini@kernel.org> References: <1494880570-14209-1-git-send-email-sstabellini@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The pvcalls backend has one ioworker per cpu: the ioworkers are implemented as a cpu bound workqueue, and will deal with the actual socket and data ring reads/writes. ioworkers are global: we only have one set for all the frontends. They process requests on their wqs list in order, once they are done with a request, they'll remove it from the list. A spinlock is used for protecting the list. Each ioworker is bound to a different cpu to maximize throughput. Signed-off-by: Stefano Stabellini CC: boris.ostrovsky@oracle.com CC: jgross@suse.com --- drivers/xen/pvcalls-back.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c index 2dbf7d8..46a889a 100644 --- a/drivers/xen/pvcalls-back.c +++ b/drivers/xen/pvcalls-back.c @@ -25,6 +25,26 @@ #include #include +struct pvcalls_ioworker { + struct work_struct register_work; + atomic_t io; + struct list_head wqs; + spinlock_t lock; + int num; +}; + +struct pvcalls_back_global { + struct pvcalls_ioworker *ioworkers; + int nr_ioworkers; + struct workqueue_struct *wq; + struct list_head privs; + struct rw_semaphore privs_lock; +} pvcalls_back_global; + +static void pvcalls_back_ioworker(struct work_struct *work) +{ +} + static int pvcalls_back_probe(struct xenbus_device *dev, const struct xenbus_device_id *id) { @@ -59,3 +79,47 @@ static int pvcalls_back_uevent(struct xenbus_device *xdev, .uevent = pvcalls_back_uevent, .otherend_changed = pvcalls_back_changed, }; + +static int __init pvcalls_back_init(void) +{ + int ret, i, cpu; + + if (!xen_domain()) + return -ENODEV; + + ret = xenbus_register_backend(&pvcalls_back_driver); + if (ret < 0) + return ret; + + init_rwsem(&pvcalls_back_global.privs_lock); + INIT_LIST_HEAD(&pvcalls_back_global.privs); + pvcalls_back_global.wq = alloc_workqueue("pvcalls_io", 0, 0); + if (!pvcalls_back_global.wq) + goto error; + pvcalls_back_global.nr_ioworkers = num_online_cpus(); + pvcalls_back_global.ioworkers = kzalloc( + sizeof(*pvcalls_back_global.ioworkers) * + pvcalls_back_global.nr_ioworkers, GFP_KERNEL); + if (!pvcalls_back_global.ioworkers) + goto error; + i = 0; + for_each_online_cpu(cpu) { + pvcalls_back_global.ioworkers[i].num = i; + atomic_set(&pvcalls_back_global.ioworkers[i].io, 1); + spin_lock_init(&pvcalls_back_global.ioworkers[i].lock); + INIT_LIST_HEAD(&pvcalls_back_global.ioworkers[i].wqs); + INIT_WORK(&pvcalls_back_global.ioworkers[i].register_work, + pvcalls_back_ioworker); + i++; + } + return 0; + +error: + if (pvcalls_back_global.wq) + destroy_workqueue(pvcalls_back_global.wq); + xenbus_unregister_driver(&pvcalls_back_driver); + kfree(pvcalls_back_global.ioworkers); + memset(&pvcalls_back_global, 0, sizeof(pvcalls_back_global)); + return -ENOMEM; +} +module_init(pvcalls_back_init); -- 1.9.1