diff options
| author |   Vadym Martsynovskyy <vmartsyn@fb.com> | 2020-06-12 09:50:50 -0700 |
|---|---|---|
| committer |   Damjan Marion <dmarion@me.com> | 2020-06-27 10:27:55 +0000 |
| commit | 42386fc974148f812ef3eb73ff09a603caa23565 (patch) | |
| tree | ed58f0e607b72aa86a0d8cc2a092fa54ef058027 | |
| parent | edc2ea435b5c407a78f4fcb42d750338d6cdd6d5 (diff) | |
udp: align udp_encap_t_ to 2 cachelines
Based on the comments in the struct, udp_encap_t_ is meant to span 2
cachelines. Due to the 64 bit alignment of dpo_id_t, the struct spanned
3 cachelines. This caused fetching ue_ip_proto to trigger an additional
cache miss. This patch rearranges the ordering of the struct fields
so that udp_encap_t_ only spans 2 cachelines as intended.
before:
(gdb) print (int)&((struct udp_encap_t_*)0)->cacheline1
$8 = 128
after:
(gdb) print (int)&((struct udp_encap_t_*)0)->cacheline1
$1 = 64
Type: fix
Signed-off-by: Vadym Martsynovskyy <vmartsyn@fb.com>
Change-Id: I066c08654d4a8ef3e2d3954e957d4c5d382b209f
| -rw-r--r-- | src/vnet/udp/udp_encap.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/src/vnet/udp/udp_encap.h b/src/vnet/udp/udp_encap.h index 888efa8c37c..9d82e59ba55 100644 --- a/src/vnet/udp/udp_encap.h +++ b/src/vnet/udp/udp_encap.h @@ -68,14 +68,14 @@ typedef struct udp_encap_t_ } __attribute__ ((packed)) ue_hdrs; /** - * Flags controlling fixup behaviour + * The DPO used to forward to the next node in the VLIB graph */ - udp_encap_fixup_flags_t ue_flags; + dpo_id_t ue_dpo; /** - * The DPO used to forward to the next node in the VLIB graph + * Flags controlling fixup behaviour */ - dpo_id_t ue_dpo; + udp_encap_fixup_flags_t ue_flags; /** * the protocol of the IP header imposed |