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author | Sujith Sankar <ssujith@cisco.com> | 2014-05-20 01:44:05 +0400 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2014-05-22 01:04:13 +0400 |
commit | 7c2ce6e60f7036de313a8c516ffe2aea889c738f (patch) | |
tree | e0d4a76efddc1bdfaab78149c145aee5d5fed2fb /drivers/net/ethernet/cisco/enic/enic.h | |
parent | f6e92d10002f584d8ec31c39aea733211bf82c0c (diff) | |
download | linux-7c2ce6e60f7036de313a8c516ffe2aea889c738f.tar.xz |
enic: Add support for adaptive interrupt coalescing
This patch adds support for adaptive interrupt coalescing.
For small pkts with low pkt rate, we can decrease the coalescing interrupt
dynamically which decreases the latency. This however increases the cpu
utilization. Based on testing with different coal intr and pkt rate we came up
with a table(mod_table) with rx_rate and coalescing interrupt value where we
get low latency without significant increase in cpu. mod_table table stores
the coalescing timer percentage value for different throughputs.
Function enic_calc_int_moderation() calculates the desired coalescing intr timer
value. This function is called in driver rx napi_poll. The actual value is set
by enic_set_int_moderation() which is called when napi_poll is complete. i.e
when we unmask the rx intr.
Adaptive coal intr is support only when driver is using msix intr. Because
intr is not shared.
Struct mod_range is used to store only the default adaptive coalescing intr
value.
Adaptive coal intr calue is calculated by
timer = range_start + ((rx_coal->range_end - range_start) *
mod_table[index].range_percent / 100);
rx_coal->range_end is the rx-usecs-high value set using ethtool.
range_start is rx-usecs-low, set using ethtool, if rx_small_pkt_bytes_cnt is
greater than 2 * rx_large_pkt_bytes_cnt. i.e small pkts are dominant. Else its
rx-usecs-low + 3.
Cc: Christian Benvenuti <benve@cisco.com>
Cc: Neel Patel <neepatel@cisco.com>
Signed-off-by: Sujith Sankar <ssujith@cisco.com>
Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/cisco/enic/enic.h')
-rw-r--r-- | drivers/net/ethernet/cisco/enic/enic.h | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/drivers/net/ethernet/cisco/enic/enic.h b/drivers/net/ethernet/cisco/enic/enic.h index e35c8e0202ad..f23ef321606c 100644 --- a/drivers/net/ethernet/cisco/enic/enic.h +++ b/drivers/net/ethernet/cisco/enic/enic.h @@ -43,6 +43,8 @@ #define ENIC_CQ_MAX (ENIC_WQ_MAX + ENIC_RQ_MAX) #define ENIC_INTR_MAX (ENIC_CQ_MAX + 2) +#define ENIC_AIC_LARGE_PKT_DIFF 3 + struct enic_msix_entry { int requested; char devname[IFNAMSIZ]; @@ -50,6 +52,33 @@ struct enic_msix_entry { void *devid; }; +/* Store only the lower range. Higher range is given by fw. */ +struct enic_intr_mod_range { + u32 small_pkt_range_start; + u32 large_pkt_range_start; +}; + +struct enic_intr_mod_table { + u32 rx_rate; + u32 range_percent; +}; + +#define ENIC_MAX_LINK_SPEEDS 3 +#define ENIC_LINK_SPEED_10G 10000 +#define ENIC_LINK_SPEED_4G 4000 +#define ENIC_LINK_40G_INDEX 2 +#define ENIC_LINK_10G_INDEX 1 +#define ENIC_LINK_4G_INDEX 0 +#define ENIC_RX_COALESCE_RANGE_END 125 +#define ENIC_AIC_TS_BREAK 100 + +struct enic_rx_coal { + u32 small_pkt_range_start; + u32 large_pkt_range_start; + u32 range_end; + u32 use_adaptive_rx_coalesce; +}; + /* priv_flags */ #define ENIC_SRIOV_ENABLED (1 << 0) @@ -92,6 +121,7 @@ struct enic { unsigned int mc_count; unsigned int uc_count; u32 port_mtu; + struct enic_rx_coal rx_coalesce_setting; u32 rx_coalesce_usecs; u32 tx_coalesce_usecs; #ifdef CONFIG_PCI_IOV |