From: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
To: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: linux-wireless@vger.kernel.org, Felix Fietkau <nbd@nbd.name>
Subject: Re: [RFC 11/12] mt76usb: allocate urb and sg as linear data
Date: Tue, 12 Mar 2019 17:34:32 +0100 [thread overview]
Message-ID: <20190312163431.GF2611@localhost.localdomain> (raw)
In-Reply-To: <1552403166-3821-12-git-send-email-sgruszka@redhat.com>
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> 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@redhat.com>
> ---
> 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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next prev parent reply other threads:[~2019-03-12 16:34 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-12 15:05 [RFC 00/12] mt76usb: some cleanups and optimizations Stanislaw Gruszka
2019-03-12 15:05 ` [RFC 01/12] mt76usb: change mt76u_submit_buf Stanislaw Gruszka
2019-03-12 15:05 ` [RFC 02/12] mt76: remove rx_page_lock Stanislaw Gruszka
2019-03-12 15:05 ` [RFC 03/12] mt76usb: change mt76u_fill_rx_sg arguments Stanislaw Gruszka
2019-03-12 15:05 ` [RFC 04/12] mt76usb: use usb_dev private data Stanislaw Gruszka
2019-03-12 15:05 ` [RFC 05/12] mt76usb: remove mt76u_buf redundant fileds Stanislaw Gruszka
2019-03-12 16:25 ` Lorenzo Bianconi
2019-03-13 12:53 ` Stanislaw Gruszka
2019-03-12 15:06 ` [RFC 06/12] mt76usb: move mt76u_buf->done to queue entry Stanislaw Gruszka
2019-03-12 15:06 ` [RFC 07/12] mt76usb: remove mt76u_buf and use urb directly Stanislaw Gruszka
2019-03-12 16:27 ` Lorenzo Bianconi
2019-03-13 12:53 ` Stanislaw Gruszka
2019-03-12 15:06 ` [RFC 08/12] mt76usb: remove MT_RXQ_MAIN queue from mt76u_urb_alloc Stanislaw Gruszka
2019-03-12 15:06 ` [RFC 09/12] mt76usb: resue mt76u_urb_alloc for tx Stanislaw Gruszka
2019-03-12 15:06 ` [RFC 10/12] mt76usb: remove unneded sg_init_table Stanislaw Gruszka
2019-03-12 15:06 ` [RFC 11/12] mt76usb: allocate urb and sg as linear data Stanislaw Gruszka
2019-03-12 16:34 ` Lorenzo Bianconi [this message]
2019-03-13 12:59 ` Stanislaw Gruszka
2019-03-12 15:06 ` [RFC 12/12] mt76usb: remove queue variable from rx_tasklet Stanislaw Gruszka
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