From 9e3f23f44f3294f794802e3fee2ba03214451a95 Mon Sep 17 00:00:00 2001 From: Jacob Keller Date: Thu, 13 Apr 2017 04:45:49 -0400 Subject: i40e: reduce wait time for adminq command completion When sending an adminq command, we wait for the command to complete in a loop. This loop waits for an entire millisecond, when in practice the adminq command is processed often much faster. Change the loop to use i40e_usec_delay instead, and wait for 50 usecs each time instead. This appears to be about the minimum time required, based on some manual observation and testing. The primary benefit of this change is reducing latency of various operations in the PF driver, especially when related to having a large number of VFs enabled. For example, on Linux, when instantiating 128 VFs, the time to finish the operation dropped from about 9 seconds down to under 6 seconds. Additionally, the time it takes to finish a PF reset with 128 VFs dropped from 5.1 seconds down to 0.7 seconds. As the examples above show, a significant portion of the delay is wasted waiting for admiqn operations which have already finished. This patch shouldn't cause impact to functionality, as we still check and keep waiting until the command does get processed. The only expected change is an increase in CPU utilization as we now check for completion far more times. However, in practice the commands appear to generally be complete within the first delay window anyways. Change-ID: If8af8388e100da0a14eaf9e1af3afadf73a958cf Signed-off-by: Jacob Keller Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/i40e/i40e_adminq.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/net/ethernet/intel/i40e/i40e_adminq.h') diff --git a/drivers/net/ethernet/intel/i40e/i40e_adminq.h b/drivers/net/ethernet/intel/i40e/i40e_adminq.h index d92aad38afdc..2349fbe04bd2 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_adminq.h +++ b/drivers/net/ethernet/intel/i40e/i40e_adminq.h @@ -151,7 +151,7 @@ static inline int i40e_aq_rc_to_posix(int aq_ret, int aq_rc) /* general information */ #define I40E_AQ_LARGE_BUF 512 -#define I40E_ASQ_CMD_TIMEOUT 250 /* msecs */ +#define I40E_ASQ_CMD_TIMEOUT 250000 /* usecs */ void i40e_fill_default_direct_cmd_desc(struct i40e_aq_desc *desc, u16 opcode); -- cgit v1.2.3