[PATCH bpf] devmap: Use GFP_KERNEL for xdp bulk queue allocation
From: NOMURA JUNICHI (野村 淳一) <hidden>
Date: 2021-02-09 08:28:26
Also in:
bpf, lkml
Subsystem:
bpf [general] (safe dynamic programs and tools), the rest, xdp (express data path) · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds, David S. Miller, Jakub Kicinski, Jesper Dangaard Brouer, John Fastabend
The devmap bulk queue is allocated with GFP_ATOMIC and the allocation may
fail if there is no available space in existing percpu pool.
Since commit 75ccae62cb8d42 ("xdp: Move devmap bulk queue into struct net_device")
moved the bulk queue allocation to NETDEV_REGISTER callback, whose context
is allowed to sleep, use GFP_KERNEL instead of GFP_ATOMIC to let percpu
allocator extend the pool when needed and avoid possible failure of netdev
registration.
As the required alignment is natural, we can simply use alloc_percpu().
Signed-off-by: Jun'ichi Nomura <redacted>
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index f6e9c68afdd4..f4d3fe8e0652 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c@@ -803,8 +803,7 @@ static int dev_map_notification(struct notifier_block *notifier, /* will be freed in free_netdev() */ netdev->xdp_bulkq = - __alloc_percpu_gfp(sizeof(struct xdp_dev_bulk_queue), - sizeof(void *), GFP_ATOMIC); + alloc_percpu(struct xdp_dev_bulk_queue); if (!netdev->xdp_bulkq) return NOTIFY_BAD;