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authorLi RongQing2020-11-24 15:21:14 +0800
committerDaniel Borkmann2020-11-25 13:18:47 +0100
commitdb13db9f67fe5049159a05e870daedcee5879f8d (patch)
tree96e63b5d852f2863129b502775d7da57e0255995
parent59e2e27d227a0a4e7ec0e22c63ca36a5ad1ab438 (diff)
libbpf: Add support for canceling cached_cons advance
Add a new function for returning descriptors the user received after an xsk_ring_cons__peek call. After the application has gotten a number of descriptors from a ring, it might not be able to or want to process them all for various reasons. Therefore, it would be useful to have an interface for returning or cancelling a number of them so that they are returned to the ring. This patch adds a new function called xsk_ring_cons__cancel that performs this operation on nb descriptors counted from the end of the batch of descriptors that was received through the peek call. Signed-off-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> [ Magnus Karlsson: rewrote changelog ] Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/1606202474-8119-1-git-send-email-lirongqing@baidu.com
-rw-r--r--tools/lib/bpf/xsk.h6
1 files changed, 6 insertions, 0 deletions
diff --git a/tools/lib/bpf/xsk.h b/tools/lib/bpf/xsk.h
index 1069c46364ff..1719a327e5f9 100644
--- a/tools/lib/bpf/xsk.h
+++ b/tools/lib/bpf/xsk.h
@@ -153,6 +153,12 @@ static inline size_t xsk_ring_cons__peek(struct xsk_ring_cons *cons,
return entries;
}
+static inline void xsk_ring_cons__cancel(struct xsk_ring_cons *cons,
+ size_t nb)
+{
+ cons->cached_cons -= nb;
+}
+
static inline void xsk_ring_cons__release(struct xsk_ring_cons *cons, size_t nb)
{
/* Make sure data has been read before indicating we are done