Messages in this thread Patch in this message | | | Date | Wed, 18 Apr 2018 10:34:26 -0400 (EDT) | From | Mikulas Patocka <> | Subject | [PATCH] net: don't use kvzalloc for DMA memory |
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The patch 74d332c13b21 changes alloc_netdev_mqs to use vzalloc if kzalloc fails (later patches change it to kvzalloc).
The problem with this is that if the vzalloc function is actually used, virtio_net doesn't work (because it expects that the extra memory should be accessible with DMA-API and memory allocated with vzalloc isn't).
This patch changes it back to kzalloc and adds a warning if the allocated size is too large (the allocation is unreliable in this case).
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Fixes: 74d332c13b21 ("net: extend net_device allocation to vmalloc()")
--- net/core/dev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
Index: linux-2.6/net/core/dev.c =================================================================== --- linux-2.6.orig/net/core/dev.c 2018-04-16 21:08:36.000000000 +0200 +++ linux-2.6/net/core/dev.c 2018-04-18 16:24:43.000000000 +0200 @@ -8366,7 +8366,8 @@ struct net_device *alloc_netdev_mqs(int /* ensure 32-byte alignment of whole construct */ alloc_size += NETDEV_ALIGN - 1; - p = kvzalloc(alloc_size, GFP_KERNEL | __GFP_RETRY_MAYFAIL); + WARN_ON(alloc_size > PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER); + p = kzalloc(alloc_size, GFP_KERNEL | __GFP_RETRY_MAYFAIL); if (!p) return NULL;
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