From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <edumazet@google.com>
Subject: Re: [PATCH v3 net-next 08/14] mlx4: use order-0 pages for RX
Date: Thu, 16 Feb 2017 09:11:01 -0800
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Cc: Tariq Toukan <tariqt@mellanox.com>,
        Jesper Dangaard Brouer <brouer@redhat.com>,
        Eric Dumazet <eric.dumazet@gmail.com>,
        Alexander Duyck <alexander.duyck@gmail.com>,
        "David S . Miller" <davem@davemloft.net>,
        netdev <netdev@vger.kernel.org>, Martin KaFai Lau <kafai@fb.com>,
        Saeed Mahameed <saeedm@mellanox.com>,
        Willem de Bruijn <willemb@google.com>,
        Brenden Blanco <bblanco@plumgrid.com>,
        Alexei Starovoitov <ast@kernel.org>,
        linux-mm <linux-mm@kvack.org>
To: Tom Herbert <tom@herbertland.com>
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> You're admitting that Eric's patches improve driver quality,
> stability, and performance but you're not allowing this in the kernel
> because "we know what benchmarks our customers are going to run".

Note that I do not particularly care if these patches go in 4.11 or 4.12 really.

I already backported them into our 4.3 based kernel.

I guess that we could at least propose the trivial patch for stable releases,
since PowerPC arches really need it.

diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index cec59bc264c9ac197048fd7c98bcd5cf25de0efd..0f6d2f3b7d54f51de359d4ccde21f4585e6b7852
100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -102,7 +102,8 @@
 /* Use the maximum between 16384 and a single page */
 #define MLX4_EN_ALLOC_SIZE     PAGE_ALIGN(16384)

-#define MLX4_EN_ALLOC_PREFER_ORDER     PAGE_ALLOC_COSTLY_ORDER
+#define MLX4_EN_ALLOC_PREFER_ORDER min_t(int, get_order(32768),
         \
+                                        PAGE_ALLOC_COSTLY_ORDER)

 /* Receive fragment sizes; we use at most 3 fragments (for 9600 byte MTU
  * and 4K allocations) */