Message ID | 20170907120556.45699-7-alice.michael@intel.com |
---|---|
State | Accepted |
Delegated to: | Jeff Kirsher |
Headers | show |
Series | [next,S80-V3,01/11] i40e: use the safe hash table iterator when deleting mac filters | expand |
> -----Original Message----- > From: Intel-wired-lan [mailto:intel-wired-lan-bounces@osuosl.org] On > Behalf Of Alice Michael > Sent: Thursday, September 7, 2017 5:06 AM > To: Michael, Alice <alice.michael@intel.com>; intel-wired- > lan@lists.osuosl.org > Subject: [Intel-wired-lan] [next PATCH S80-V3 07/11] i40e/i40evf: bundle > more descriptors when allocating buffers > > From: Jacob Keller <jacob.e.keller@intel.com> > > Double the number of descriptors we'll bundle into one tail bump when > receiving. Empirical testing has shown that we reduce CPU utilization and > don't appear to reduce throughput or packet rate. 32 seems to be the sweet > spot, as it's half the default polling budget, so we'd essentially reduce from 4 > tail writes when polling down to 2. Increasing this up to > 64 appears to have negative impacts as it may become possible that we don't > bump the tail each time we get polled, which could cause a long delay > between returning descriptors to the hardware. > > Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> > --- > drivers/net/ethernet/intel/i40e/i40e_txrx.h | 2 +- > drivers/net/ethernet/intel/i40evf/i40e_txrx.h | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h b/drivers/net/ethernet/intel/i40e/i40e_txrx.h index c3156aa..ff57ae4 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h @@ -208,7 +208,7 @@ static inline bool i40e_test_staterr(union i40e_rx_desc *rx_desc, } /* How many Rx Buffers do we bundle into one write to the hardware ? */ -#define I40E_RX_BUFFER_WRITE 16 /* Must be power of 2 */ +#define I40E_RX_BUFFER_WRITE 32 /* Must be power of 2 */ #define I40E_RX_INCREMENT(r, i) \ do { \ (i)++; \ diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h index 8f9830d..8d26c85 100644 --- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h +++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h @@ -191,7 +191,7 @@ static inline bool i40e_test_staterr(union i40e_rx_desc *rx_desc, } /* How many Rx Buffers do we bundle into one write to the hardware ? */ -#define I40E_RX_BUFFER_WRITE 16 /* Must be power of 2 */ +#define I40E_RX_BUFFER_WRITE 32 /* Must be power of 2 */ #define I40E_RX_INCREMENT(r, i) \ do { \ (i)++; \