Re: [PATCH 3/3] vhost: apply cpumask and cgroup to vhost pollers
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2010-06-24 08:17:20
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On Sun, May 30, 2010 at 10:25:01PM +0200, Tejun Heo wrote:
Apply the cpumask and cgroup of the initializing task to the created vhost poller. Based on Sridhar Samudrala's patch. Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Sridhar Samudrala <redacted>
I wanted to apply this, but modpost fails: ERROR: "sched_setaffinity" [drivers/vhost/vhost_net.ko] undefined! ERROR: "sched_getaffinity" [drivers/vhost/vhost_net.ko] undefined! Did you try building as a module?
quoted hunk ↗ jump to hunk
--- drivers/vhost/vhost.c | 36 +++++++++++++++++++++++++++++++----- 1 file changed, 31 insertions(+), 5 deletions(-) Index: work/drivers/vhost/vhost.c ===================================================================--- work.orig/drivers/vhost/vhost.c +++ work/drivers/vhost/vhost.c@@ -23,6 +23,7 @@ #include <linux/highmem.h> #include <linux/slab.h> #include <linux/kthread.h> +#include <linux/cgroup.h> #include <linux/net.h> #include <linux/if_packet.h>@@ -176,12 +177,30 @@ repeat: long vhost_dev_init(struct vhost_dev *dev, struct vhost_virtqueue *vqs, int nvqs) { - struct task_struct *poller; - int i; + struct task_struct *poller = NULL; + cpumask_var_t mask; + int i, ret = -ENOMEM; + + if (!alloc_cpumask_var(&mask, GFP_KERNEL)) + goto out; 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; + } + + ret = sched_getaffinity(current->pid, mask); + if (ret) + goto out; + + ret = sched_setaffinity(poller->pid, mask); + if (ret) + goto out; + + ret = cgroup_attach_task_current_cg(poller); + if (ret) + goto out; dev->vqs = vqs; dev->nvqs = nvqs;@@ -202,7 +221,14 @@ 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; +out: + if (ret) + kthread_stop(poller); + free_cpumask_var(mask); + return ret; } /* Caller should have device mutex */