From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH UPDATED2 3/3] vhost: apply cpumask and cgroup to vhost pollers Date: Mon, 31 May 2010 12:20:39 +0200 Message-ID: <4C038D77.3060508@kernel.org> References: <20100527091426.GA6308@redhat.com> <20100527124448.GA4241@redhat.com> <20100527131254.GB7974@redhat.com> <4BFE9ABA.6030907@kernel.org> <20100527163954.GA21710@redhat.com> <4BFEA434.6080405@kernel.org> <20100527173207.GA21880@redhat.com> <4BFEE216.2070807@kernel.org> <20100528150830.GB21880@redhat.com> <4BFFE742.2060205@kernel.org> <20100530112925.GB27611@redhat.com> <4C02C99D.9070204@kernel.org> <4C030CB8.505@cn.fujitsu.com> <4C035E22.9010001@kernel.org> <4C0369CD.70008@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "Michael S. Tsirkin" , Oleg Nesterov , Sridhar Samudrala , netdev , lkml , "kvm@vger.kernel.org" , Andrew Morton , Dmitri Vorobiev , Jiri Kosina , Thomas Gleixner , Ingo Molnar , Andi Kleen To: Li Zefan Return-path: In-Reply-To: <4C0369CD.70008@cn.fujitsu.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Apply the cpumask and cgroup of the initializing task to the created vhost poller. Based on Sridhar Samudrala's patch. Li Zefan spotted a bug in error path (twice), fixed (twice). Cc: Michael S. Tsirkin Cc: Sridhar Samudrala Cc: Li Zefan --- Heh... that's embarrassing. Let's see if I can get it right the third time. Thank you. drivers/vhost/vhost.c | 36 ++++++++++++++++++++++++++++++++---- 1 file changed, 32 insertions(+), 4 deletions(-) Index: work/drivers/vhost/vhost.c =================================================================== --- work.orig/drivers/vhost/vhost.c +++ work/drivers/vhost/vhost.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include @@ -177,11 +178,29 @@ long vhost_dev_init(struct vhost_dev *de struct vhost_virtqueue *vqs, int nvqs) { struct task_struct *poller; - int i; + cpumask_var_t mask; + int i, ret = -ENOMEM; + + if (!alloc_cpumask_var(&mask, GFP_KERNEL)) + goto out_free_mask; poller = kthread_create(vhost_poller, dev, "vhost-%d", current->pid); - if (IS_ERR(poller)) - return PTR_ERR(poller); + if (IS_ERR(poller)) { + ret = PTR_ERR(poller); + goto out_free_mask; + } + + ret = sched_getaffinity(current->pid, mask); + if (ret) + goto out_stop_poller; + + ret = sched_setaffinity(poller->pid, mask); + if (ret) + goto out_stop_poller; + + ret = cgroup_attach_task_current_cg(poller); + if (ret) + goto out_stop_poller; dev->vqs = vqs; dev->nvqs = nvqs; @@ -202,7 +221,16 @@ long vhost_dev_init(struct vhost_dev *de vhost_poll_init(&dev->vqs[i].poll, dev->vqs[i].handle_kick, POLLIN, dev); } - return 0; + + wake_up_process(poller); /* avoid contributing to loadavg */ + ret = 0; + goto out_free_mask; + +out_stop_poller: + kthread_stop(poller); +out_free_mask: + free_cpumask_var(mask); + return ret; } /* Caller should have device mutex */