From 2ca200501e3e58a8f7d2497ff9ba5a39f2f47014 Mon Sep 17 00:00:00 2001 From: Andrew Yourtchenko Date: Wed, 7 Mar 2018 17:35:59 +0100 Subject: [PATCH] vnet: l2-classify: prefetch (n+2, n+3) rather than (n+1, n+2) inside dual loop code The dual loop within the L2 classifier processes the (n, n+1) packets, the prefetching was trying to prefetch (n+1, n+2) - thus half of the prefetches were not used - because the next iteration needs (n+2, n+3). Change-Id: I827d20845dbdd0dcdcf463ee25661a7921428992 Signed-off-by: Andrew Yourtchenko --- src/vnet/l2/l2_input_classify.c | 10 +++++----- src/vnet/l2/l2_output_classify.c | 10 +++++----- 2 files changed, 10 insertions(+), 10 deletions(-) diff --git a/src/vnet/l2/l2_input_classify.c b/src/vnet/l2/l2_input_classify.c index ee8042a064e..fcf4783bc1e 100644 --- a/src/vnet/l2/l2_input_classify.c +++ b/src/vnet/l2/l2_input_classify.c @@ -167,7 +167,7 @@ l2_input_classify_node_fn (vlib_main_t * vm, /* First pass: compute hash */ - while (n_left_from > 2) + while (n_left_from >= 4) { vlib_buffer_t *b0, *b1; u32 bi0, bi1; @@ -182,15 +182,15 @@ l2_input_classify_node_fn (vlib_main_t * vm, /* prefetch next iteration */ { - vlib_buffer_t *p1, *p2; + vlib_buffer_t *p2, *p3; - p1 = vlib_get_buffer (vm, from[1]); p2 = vlib_get_buffer (vm, from[2]); + p3 = vlib_get_buffer (vm, from[3]); - vlib_prefetch_buffer_header (p1, STORE); - CLIB_PREFETCH (p1->data, CLIB_CACHE_LINE_BYTES, STORE); vlib_prefetch_buffer_header (p2, STORE); CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE); + vlib_prefetch_buffer_header (p3, STORE); + CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE); } bi0 = from[0]; diff --git a/src/vnet/l2/l2_output_classify.c b/src/vnet/l2/l2_output_classify.c index a49abec2781..338fe849660 100644 --- a/src/vnet/l2/l2_output_classify.c +++ b/src/vnet/l2/l2_output_classify.c @@ -160,7 +160,7 @@ l2_output_classify_node_fn (vlib_main_t * vm, /* First pass: compute hash */ - while (n_left_from > 2) + while (n_left_from >= 4) { vlib_buffer_t *b0, *b1; u32 bi0, bi1; @@ -175,15 +175,15 @@ l2_output_classify_node_fn (vlib_main_t * vm, /* prefetch next iteration */ { - vlib_buffer_t *p1, *p2; + vlib_buffer_t *p2, *p3; - p1 = vlib_get_buffer (vm, from[1]); p2 = vlib_get_buffer (vm, from[2]); + p3 = vlib_get_buffer (vm, from[3]); - vlib_prefetch_buffer_header (p1, STORE); - CLIB_PREFETCH (p1->data, CLIB_CACHE_LINE_BYTES, STORE); vlib_prefetch_buffer_header (p2, STORE); CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE); + vlib_prefetch_buffer_header (p3, STORE); + CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE); } bi0 = from[0]; -- 2.16.6