> Alloc sg table at the end of urb structure. This will increase
> cache usage.
>
I am curious, have you observed any performance improvement doing so?
> Signed-off-by: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
> ---
> drivers/net/wireless/mediatek/mt76/usb.c | 20 ++++++++++----------
> 1 file changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/net/wireless/mediatek/mt76/usb.c b/drivers/net/wireless/mediatek/mt76/usb.c
> index 0b9f0b5fd37d..dd487f65f44e 100644
> --- a/drivers/net/wireless/mediatek/mt76/usb.c
> +++ b/drivers/net/wireless/mediatek/mt76/usb.c
> @@ -336,19 +336,19 @@ static bool mt76u_check_sg(struct mt76_dev *dev)
> static int
> mt76u_urb_alloc(struct mt76_dev *dev, struct mt76_queue_entry *e)
> {
> - struct urb *urb;
> + unsigned int size = sizeof(struct urb);
> +
> + if (dev->usb.sg_en)
> + size += MT_SG_MAX_SIZE * sizeof(struct scatterlist);
>
> - urb = usb_alloc_urb(0, GFP_KERNEL);
> - if (!urb)
> + e->urb = kzalloc(size, GFP_KERNEL);
> + if (!e->urb)
> return -ENOMEM;
> - e->urb = urb;
>
> - if (dev->usb.sg_en) {
> - urb->sg = devm_kcalloc(dev->dev, MT_SG_MAX_SIZE,
> - sizeof(urb->sg), GFP_KERNEL);
> - if (!urb->sg)
> - return -ENOMEM;
> - }
> + usb_init_urb(e->urb);
> +
> + if (dev->usb.sg_en)
> + e->urb->sg = (struct scatterlist *)((u8 *)e->urb + sizeof(struct urb));
You can avoid u8 cast doing:
(struct scatterlist *)(e->urb + 1)
Regards,
Lorenzo
>
> return 0;
> }
> --
> 1.9.3
>
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