Re: [PATCH v2 net-next 05/15] net: sgi: ioc3-eth: allocate space for desc rings only once

From: Thomas Bogendoerfer
Date: Thu Aug 29 2019 - 18:01:02 EST


On Thu, 29 Aug 2019 14:05:37 -0700
Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx> wrote:

> On Thu, 29 Aug 2019 17:50:03 +0200, Thomas Bogendoerfer wrote:
> > + if (skb)
> > + dev_kfree_skb_any(skb);
>
> I think dev_kfree_skb_any() accepts NULL

yes, I'll drop the if

> > +
> > + /* Allocate and rx ring. 4kb = 512 entries */
> > + ip->rxr = (unsigned long *)get_zeroed_page(GFP_ATOMIC);
> > + if (!ip->rxr) {
> > + pr_err("ioc3-eth: rx ring allocation failed\n");
> > + err = -ENOMEM;
> > + goto out_stop;
> > + }
> > +
> > + /* Allocate tx rings. 16kb = 128 bufs. */
> > + ip->txr = (struct ioc3_etxd *)__get_free_pages(GFP_KERNEL, 2);
> > + if (!ip->txr) {
> > + pr_err("ioc3-eth: tx ring allocation failed\n");
> > + err = -ENOMEM;
> > + goto out_stop;
> > + }
>
> Please just use kcalloc()/kmalloc_array() here,

both allocation will be replaced in patch 11 with dma_direct_alloc_pages.
So I hope I don't need to change it here.

Out of curiosity does kcalloc/kmalloc_array give me the same guarantees about
alignment ? rx ring needs to be 4KB aligned, tx ring 16KB aligned.

>, and make sure the flags
> are set to GFP_KERNEL whenever possible. Here and in ioc3_alloc_rings()
> it looks like GFP_ATOMIC is unnecessary.

yes, I'll change it

Thomas.

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