From 28aa539f7da7b172d0f35ea9a63f3986939477f7 Mon Sep 17 00:00:00 2001 From: Sirshak Das Date: Tue, 5 Feb 2019 01:33:33 -0600 Subject: svm_fifo rework to avoid contention on cursize Problems Addressed: - Contention of cursize by producer and consumer. - Reduce the no of modulo operations. Changes: - Synchronization between producer and consumer changed from cursize to head and tail indexes Implications: reduces the usable size of fifo by 1. - Using weaker memory ordering C++11 atomics to access head and tail based on producer and consumer role. - Head and tail indexes are unsigned 32 bit integers. Additions and subtraction on them are implicit 32 bit Modulo operation. - Adding weaker memory ordering variants of max_enq, max_deq, is_empty and is_full Using them appropriately in all places. Perfomance improvement (iperf3 via Hoststack): iperf3 Server: Marvell ThunderX2(AArch64) - iperf3 Client: Skylake(x86) ~6%(256 rxd/txd) - ~11%(2048 rxd/txd) Change-Id: I1d484e000e437430fdd5a819657d1c6b62443018 Signed-off-by: Sirshak Das Reviewed-by: Honnappa Nagarahalli --- src/vnet/tcp/tcp_input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src/vnet/tcp') diff --git a/src/vnet/tcp/tcp_input.c b/src/vnet/tcp/tcp_input.c index f838bc562ff..3d40c062a87 100644 --- a/src/vnet/tcp/tcp_input.c +++ b/src/vnet/tcp/tcp_input.c @@ -1871,7 +1871,7 @@ tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b, newest = svm_fifo_newest_ooo_segment (s0->rx_fifo); if (newest) { - offset = ooo_segment_offset (s0->rx_fifo, newest); + offset = ooo_segment_offset_prod (s0->rx_fifo, newest); ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt); start = tc->rcv_nxt + offset; end = start + ooo_segment_length (s0->rx_fifo, newest); -- cgit 1.2.3-korg