From cc95d45388990b1b28acfc90e86a926760f01f16 Mon Sep 17 00:00:00 2001 From: np Date: Fri, 12 Sep 2014 05:25:56 +0000 Subject: cxgbe(4): knobs to enable/disable PAUSE frame based flow control. MFC after: 1 week --- share/man/man4/cxgbe.4 | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'share') diff --git a/share/man/man4/cxgbe.4 b/share/man/man4/cxgbe.4 index 215a194..9a9f868 100644 --- a/share/man/man4/cxgbe.4 +++ b/share/man/man4/cxgbe.4 @@ -240,8 +240,19 @@ The default is -1 which lets the driver pick a pad boundary. Controls the hardware response to congestion. -1 disables congestion feedback and is not recommended. 0 instructs the hardware to backpressure its pipeline on congestion. -This usually results in the port emitting pause frames. +This usually results in the port emitting PAUSE frames. 1 instructs the hardware to drop frames destined for congested queues. +.It Va hw.cxgbe.pause_settings +PAUSE frame settings. +Bit 0 is rx_pause, bit 1 is tx_pause. +rx_pause = 1 instructs the hardware to heed incoming PAUSE frames, 0 instructs +it to ignore them. +tx_pause = 1 allows the hardware to emit PAUSE frames when its receive FIFO +reaches a high threshold, 0 prohibits the hardware from emitting PAUSE frames. +The default is 3 (both rx_pause and tx_pause = 1). +This tunable establishes the default PAUSE settings for all ports. +Settings can be displayed and controlled on a per-port basis via the +dev.cxgbe.X.pause_settings (dev.cxl.X.pause_settings for T5 cards) sysctl. .It Va hw.cxgbe.buffer_packing Allow the hardware to deliver multiple frames in the same receive buffer opportunistically. -- cgit v1.1