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authorTal Gilboa <talgi@mellanox.com>2018-11-04 19:07:02 +0200
committerSaeed Mahameed <saeedm@mellanox.com>2019-06-25 13:46:38 -0700
commit0e58983de0d89f6ee75daab1b0ea918cfcf6ddbf (patch)
treec0ddad37cb31cee6a1ee1420d47a4405baf79d24 /include/linux/dim.h
parentcd6c84d8f0cdc911df435bb075ba22ce3c605b07 (diff)
linux/dim: Move logic to dim.h
In preparation for supporting more implementations of the DIM algorithm, I'm moving what would become common logic to a common library. Downstream DIM implementations will use the common lib for their implementation. Signed-off-by: Tal Gilboa <talgi@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Diffstat (limited to 'include/linux/dim.h')
-rw-r--r--include/linux/dim.h153
1 files changed, 153 insertions, 0 deletions
diff --git a/include/linux/dim.h b/include/linux/dim.h
new file mode 100644
index 000000000000..67d7ca40f3dd
--- /dev/null
+++ b/include/linux/dim.h
@@ -0,0 +1,153 @@
+/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
+/* Copyright (c) 2019 Mellanox Technologies. */
+
+#ifndef DIM_H
+#define DIM_H
+
+#include <linux/module.h>
+
+#define NET_DIM_NEVENTS 64
+
+/* more than 10% difference */
+#define IS_SIGNIFICANT_DIFF(val, ref) \
+ (((100UL * abs((val) - (ref))) / (ref)) > 10)
+#define BIT_GAP(bits, end, start) ((((end) - (start)) + BIT_ULL(bits)) \
+& (BIT_ULL(bits) - 1))
+
+struct net_dim_cq_moder {
+ u16 usec;
+ u16 pkts;
+ u8 cq_period_mode;
+};
+
+struct net_dim_sample {
+ ktime_t time;
+ u32 pkt_ctr;
+ u32 byte_ctr;
+ u16 event_ctr;
+};
+
+struct net_dim_stats {
+ int ppms; /* packets per msec */
+ int bpms; /* bytes per msec */
+ int epms; /* events per msec */
+};
+
+struct net_dim { /* Dynamic Interrupt Moderation */
+ u8 state;
+ struct net_dim_stats prev_stats;
+ struct net_dim_sample start_sample;
+ struct work_struct work;
+ u8 profile_ix;
+ u8 mode;
+ u8 tune_state;
+ u8 steps_right;
+ u8 steps_left;
+ u8 tired;
+};
+
+enum {
+ NET_DIM_CQ_PERIOD_MODE_START_FROM_EQE = 0x0,
+ NET_DIM_CQ_PERIOD_MODE_START_FROM_CQE = 0x1,
+ NET_DIM_CQ_PERIOD_NUM_MODES
+};
+
+enum {
+ NET_DIM_START_MEASURE,
+ NET_DIM_MEASURE_IN_PROGRESS,
+ NET_DIM_APPLY_NEW_PROFILE,
+};
+
+enum {
+ NET_DIM_PARKING_ON_TOP,
+ NET_DIM_PARKING_TIRED,
+ NET_DIM_GOING_RIGHT,
+ NET_DIM_GOING_LEFT,
+};
+
+enum {
+ NET_DIM_STATS_WORSE,
+ NET_DIM_STATS_SAME,
+ NET_DIM_STATS_BETTER,
+};
+
+enum {
+ NET_DIM_STEPPED,
+ NET_DIM_TOO_TIRED,
+ NET_DIM_ON_EDGE,
+};
+
+static inline bool net_dim_on_top(struct net_dim *net_dim)
+{
+ switch (net_dim->tune_state) {
+ case NET_DIM_PARKING_ON_TOP:
+ case NET_DIM_PARKING_TIRED:
+ return true;
+ case NET_DIM_GOING_RIGHT:
+ return (net_dim->steps_left > 1) && (net_dim->steps_right == 1);
+ default: /* NET_DIM_GOING_LEFT */
+ return (net_dim->steps_right > 1) && (net_dim->steps_left == 1);
+ }
+}
+
+static inline void net_dim_turn(struct net_dim *net_dim)
+{
+ switch (net_dim->tune_state) {
+ case NET_DIM_PARKING_ON_TOP:
+ case NET_DIM_PARKING_TIRED:
+ break;
+ case NET_DIM_GOING_RIGHT:
+ net_dim->tune_state = NET_DIM_GOING_LEFT;
+ net_dim->steps_left = 0;
+ break;
+ case NET_DIM_GOING_LEFT:
+ net_dim->tune_state = NET_DIM_GOING_RIGHT;
+ net_dim->steps_right = 0;
+ break;
+ }
+}
+
+static inline void net_dim_park_on_top(struct net_dim *net_dim)
+{
+ net_dim->steps_right = 0;
+ net_dim->steps_left = 0;
+ net_dim->tired = 0;
+ net_dim->tune_state = NET_DIM_PARKING_ON_TOP;
+}
+
+static inline void net_dim_park_tired(struct net_dim *net_dim)
+{
+ net_dim->steps_right = 0;
+ net_dim->steps_left = 0;
+ net_dim->tune_state = NET_DIM_PARKING_TIRED;
+}
+
+static inline void
+net_dim_sample(u16 event_ctr, u64 packets, u64 bytes, struct net_dim_sample *s)
+{
+ s->time = ktime_get();
+ s->pkt_ctr = packets;
+ s->byte_ctr = bytes;
+ s->event_ctr = event_ctr;
+}
+
+static inline void
+net_dim_calc_stats(struct net_dim_sample *start, struct net_dim_sample *end,
+ struct net_dim_stats *curr_stats)
+{
+ /* u32 holds up to 71 minutes, should be enough */
+ u32 delta_us = ktime_us_delta(end->time, start->time);
+ u32 npkts = BIT_GAP(BITS_PER_TYPE(u32), end->pkt_ctr, start->pkt_ctr);
+ u32 nbytes = BIT_GAP(BITS_PER_TYPE(u32), end->byte_ctr,
+ start->byte_ctr);
+
+ if (!delta_us)
+ return;
+
+ curr_stats->ppms = DIV_ROUND_UP(npkts * USEC_PER_MSEC, delta_us);
+ curr_stats->bpms = DIV_ROUND_UP(nbytes * USEC_PER_MSEC, delta_us);
+ curr_stats->epms = DIV_ROUND_UP(NET_DIM_NEVENTS * USEC_PER_MSEC,
+ delta_us);
+}
+
+#endif /* DIM_H */