Re: [PATCH] vhost/scsi: use vmalloc for order-10 allocation
From: Sergei Shtylyov <hidden>
Date: 2013-09-17 18:14:41
Also in:
kvm, lkml, virtualization
Hello. On 09/17/2013 11:21 AM, Michael S. Tsirkin wrote:
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.
Reported-by: Dan Aloni <redacted> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> ---
I put this on my vhost fixes branch, intend to merge for 3.12. Dan, could you please confirm this works for you?
drivers/vhost/scsi.c | 41 +++++++++++++++++++++++++++-------------- 1 file changed, 27 insertions(+), 14 deletions(-)
quoted hunk ↗ jump to hunk
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index 4b79a1f..2c30bb0 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c@@ -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);
Indent with the tabs ISO spaces, please.
+}
+
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);
Indent here with a tab, please.
+ if (!vs) {
+ vs = vzalloc(sizeof(*vs));
+ if (!vs)
+ goto err_vs;
+ }WBR, Sergei