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 <mst@xxxxxxxxxx>
Cc: Sridhar Samudrala <samudrala.sridhar@xxxxxxxxx>
Cc: Li Zefan <lizf@xxxxxxxxxxxxxx>
---
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 <linux/highmem.h>
#include <linux/slab.h>
#include <linux/kthread.h>
+#include <linux/cgroup.h>
#include <linux/net.h>
#include <linux/if_packet.h>
@@ -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 */
--
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