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vhost/scsi: use vmalloc for order-10 allocation

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As vhost scsi device struct is large, if the device is
created on a busy system, kzalloc() might fail, so this patch does a
fallback to vzalloc().

As vmalloc() adds overhead on data-path, add __GFP_REPEAT
to kzalloc() flags to do this fallback only when really needed.

Reviewed-by: Asias He <asias@redhat.com>
Reported-by: Dan Aloni <alonid@stratoscale.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2013-09-17 09:30:34 +03:00
parent ac9fde2474
commit 595cb75498
1 changed files with 27 additions and 14 deletions
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41
drivers/vhost/scsi.c
View file

@ -1373,21 +1373,30 @@ static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
return 0;
}
static void vhost_scsi_free(struct vhost_scsi *vs)
{
if (is_vmalloc_addr(vs))
vfree(vs);
else
kfree(vs);
}
static int vhost_scsi_open(struct inode *inode, struct file *f)
{
struct vhost_scsi *vs;
struct vhost_virtqueue **vqs;
int r, i;
int r = -ENOMEM, i;
vs = kzalloc(sizeof(*vs), GFP_KERNEL);
if (!vs)
return -ENOMEM;
vs = kzalloc(sizeof(*vs), GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
if (!vs) {
vs = vzalloc(sizeof(*vs));
if (!vs)
goto err_vs;
}
vqs = kmalloc(VHOST_SCSI_MAX_VQ * sizeof(*vqs), GFP_KERNEL);
if (!vqs) {
kfree(vs);
return -ENOMEM;
}
if (!vqs)
goto err_vqs;
vhost_work_init(&vs->vs_completion_work, vhost_scsi_complete_cmd_work);
vhost_work_init(&vs->vs_event_work, tcm_vhost_evt_work);
@ -1407,14 +1416,18 @@ static int vhost_scsi_open(struct inode *inode, struct file *f)
tcm_vhost_init_inflight(vs, NULL);
if (r < 0) {
kfree(vqs);
kfree(vs);
return r;
}
if (r < 0)
goto err_init;
f->private_data = vs;
return 0;
err_init:
kfree(vqs);
err_vqs:
vhost_scsi_free(vs);
err_vs:
return r;
}
static int vhost_scsi_release(struct inode *inode, struct file *f)
@ -1431,7 +1444,7 @@ static int vhost_scsi_release(struct inode *inode, struct file *f)
/* Jobs can re-queue themselves in evt kick handler. Do extra flush. */
vhost_scsi_flush(vs);
kfree(vs->dev.vqs);
kfree(vs);
vhost_scsi_free(vs);
return 0;
}