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authorMagnus Karlsson <magnus.karlsson@intel.com>2019-12-19 13:39:20 +0100
committerAlexei Starovoitov <ast@kernel.org>2019-12-20 16:00:08 -0800
commit484b165306e18fd9a0d960e6ed2d6eff31665522 (patch)
treecbbe2f1c2d13b417c914c3a0725843b36cd7966a /net/xdp
parentMerge branch 'replace-cg_bpf-prog' (diff)
downloadlinux-dev-484b165306e18fd9a0d960e6ed2d6eff31665522.tar.xz
linux-dev-484b165306e18fd9a0d960e6ed2d6eff31665522.zip
xsk: Eliminate the lazy update threshold
The lazy update threshold was introduced to keep the producer and consumer some distance apart in the completion ring. This was important in the beginning of the development of AF_XDP as the ring format as that point in time was very sensitive to the producer and consumer being on the same cache line. This is not the case anymore as the current ring format does not degrade in any noticeable way when this happens. Moreover, this threshold makes it impossible to run the system with rings that have less than 128 entries. So let us remove this threshold and just get one entry from the ring as in all other functions. This will enable us to remove this function in a later commit. Note that xskq_produce_addr_lazy followed by xskq_produce_flush_addr_n are still not the same function as xskq_produce_addr() as it operates on another cached pointer. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1576759171-28550-2-git-send-email-magnus.karlsson@intel.com
Diffstat (limited to 'net/xdp')
-rw-r--r--net/xdp/xsk_queue.h3
1 files changed, 1 insertions, 2 deletions
diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
index eddae4688862..a2f0ba65559f 100644
--- a/net/xdp/xsk_queue.h
+++ b/net/xdp/xsk_queue.h
@@ -11,7 +11,6 @@
#include <net/xdp_sock.h>
#define RX_BATCH_SIZE 16
-#define LAZY_UPDATE_THRESHOLD 128
struct xdp_ring {
u32 producer ____cacheline_aligned_in_smp;
@@ -239,7 +238,7 @@ static inline int xskq_produce_addr_lazy(struct xsk_queue *q, u64 addr)
{
struct xdp_umem_ring *ring = (struct xdp_umem_ring *)q->ring;
- if (xskq_nb_free(q, q->prod_head, LAZY_UPDATE_THRESHOLD) == 0)
+ if (xskq_nb_free(q, q->prod_head, 1) == 0)
return -ENOSPC;
/* A, matches D */