diff options
| author | Ben Hutchings <bhutchings@solarflare.com> | 2009-03-20 16:30:37 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-03-22 05:06:58 +0300 |
| commit | 6fb70fd1b57707a5c7b9fb167b7790b2cba13f04 (patch) | |
| tree | 311192bd4de07e1da571f1a6ac6a3ad123ab3f50 /drivers/net/sfc/efx.c | |
| parent | 85451a951b9511605475fadcc0a8d3aeccefded8 (diff) | |
| download | linux-6fb70fd1b57707a5c7b9fb167b7790b2cba13f04.tar.xz | |
sfc: Implement adaptive IRQ moderation
Calculate a score for each 1000 IRQs:
- TX completions are worth 1 point
- RX completions are worth 4 if merged using LRO or 2 otherwise
Reduce moderation if the score is less than 10000, down to a minimum
of 5 us. Increase moderation if the score is more than 20000, up to
the specified maximum.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/sfc/efx.c')
| -rw-r--r-- | drivers/net/sfc/efx.c | 46 |
1 files changed, 44 insertions, 2 deletions
diff --git a/drivers/net/sfc/efx.c b/drivers/net/sfc/efx.c index 8fa68d82c022..6eff9ca6c6c8 100644 --- a/drivers/net/sfc/efx.c +++ b/drivers/net/sfc/efx.c @@ -133,6 +133,16 @@ static int phy_flash_cfg; module_param(phy_flash_cfg, int, 0644); MODULE_PARM_DESC(phy_flash_cfg, "Set PHYs into reflash mode initially"); +static unsigned irq_adapt_low_thresh = 10000; +module_param(irq_adapt_low_thresh, uint, 0644); +MODULE_PARM_DESC(irq_adapt_low_thresh, + "Threshold score for reducing IRQ moderation"); + +static unsigned irq_adapt_high_thresh = 20000; +module_param(irq_adapt_high_thresh, uint, 0644); +MODULE_PARM_DESC(irq_adapt_high_thresh, + "Threshold score for increasing IRQ moderation"); + /************************************************************************** * * Utility functions and prototypes @@ -223,6 +233,35 @@ static int efx_poll(struct napi_struct *napi, int budget) rx_packets = efx_process_channel(channel, budget); if (rx_packets < budget) { + struct efx_nic *efx = channel->efx; + + if (channel->used_flags & EFX_USED_BY_RX && + efx->irq_rx_adaptive && + unlikely(++channel->irq_count == 1000)) { + unsigned old_irq_moderation = channel->irq_moderation; + + if (unlikely(channel->irq_mod_score < + irq_adapt_low_thresh)) { + channel->irq_moderation = + max_t(int, + channel->irq_moderation - + FALCON_IRQ_MOD_RESOLUTION, + FALCON_IRQ_MOD_RESOLUTION); + } else if (unlikely(channel->irq_mod_score > + irq_adapt_high_thresh)) { + channel->irq_moderation = + min(channel->irq_moderation + + FALCON_IRQ_MOD_RESOLUTION, + efx->irq_rx_moderation); + } + + if (channel->irq_moderation != old_irq_moderation) + falcon_set_int_moderation(channel); + + channel->irq_count = 0; + channel->irq_mod_score = 0; + } + /* There is no race here; although napi_disable() will * only wait for napi_complete(), this isn't a problem * since efx_channel_processed() will have no effect if @@ -991,7 +1030,7 @@ static int efx_probe_nic(struct efx_nic *efx) efx_set_channels(efx); /* Initialise the interrupt moderation settings */ - efx_init_irq_moderation(efx, tx_irq_mod_usec, rx_irq_mod_usec); + efx_init_irq_moderation(efx, tx_irq_mod_usec, rx_irq_mod_usec, true); return 0; } @@ -1188,7 +1227,8 @@ void efx_flush_queues(struct efx_nic *efx) **************************************************************************/ /* Set interrupt moderation parameters */ -void efx_init_irq_moderation(struct efx_nic *efx, int tx_usecs, int rx_usecs) +void efx_init_irq_moderation(struct efx_nic *efx, int tx_usecs, int rx_usecs, + bool rx_adaptive) { struct efx_tx_queue *tx_queue; struct efx_rx_queue *rx_queue; @@ -1198,6 +1238,8 @@ void efx_init_irq_moderation(struct efx_nic *efx, int tx_usecs, int rx_usecs) efx_for_each_tx_queue(tx_queue, efx) tx_queue->channel->irq_moderation = tx_usecs; + efx->irq_rx_adaptive = rx_adaptive; + efx->irq_rx_moderation = rx_usecs; efx_for_each_rx_queue(rx_queue, efx) rx_queue->channel->irq_moderation = rx_usecs; } |