netdev - Re: [PATCH] net: ethernet: et131x: Use GFP_KERNEL instead of GFP_ATOMIC when allocating tx_ring->tcb

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Date:   Thu, 8 Aug 2019 04:24:35 -0700
From:   Matthew Wilcox <willy@...radead.org>
To:     Jesse Brandeburg <jesse.brandeburg@...el.com>
Cc:     Christophe JAILLET <christophe.jaillet@...adoo.fr>,
        mark.einon@...il.com, davem@...emloft.net, f.fainelli@...il.com,
        andrew@...n.ch, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org, kernel-janitors@...r.kernel.org
Subject: Re: [PATCH] net: ethernet: et131x: Use GFP_KERNEL instead of
 GFP_ATOMIC when allocating tx_ring->tcb_ring

On Wed, Aug 07, 2019 at 10:23:46PM -0700, Jesse Brandeburg wrote:
> On Wed, 31 Jul 2019 09:38:42 +0200
> Christophe JAILLET <christophe.jaillet@...adoo.fr> wrote:
> 
> > There is no good reason to use GFP_ATOMIC here. Other memory allocations
> > are performed with GFP_KERNEL (see other 'dma_alloc_coherent()' below and
> > 'kzalloc()' in 'et131x_rx_dma_memory_alloc()')
> > 
> > Use GFP_KERNEL which should be enough.
> > 
> > Signed-off-by: Christophe JAILLET <christophe.jaillet@...adoo.fr>
> 
> Sure, but generally I'd say GFP_ATOMIC is ok if you're in an init path
> and you can afford to have the allocation thread sleep while memory is
> being found by the kernel.

That's not what GFP_ATOMIC means.  GFP_ATOMIC _will not_ sleep.  GFP_KERNEL
will.