mirror of
https://github.com/torvalds/linux.git
synced 2024-11-22 12:11:40 +00:00
162bd18eb5
Add return value for dim_calc_stats. This is an indication for the
caller if curr_stats was assigned by the function. Avoid using
curr_stats uninitialized over {rdma/net}_dim, when no time delta between
samples. Coverity reported this potential use of an uninitialized
variable.
Fixes: 4c4dbb4a73 ("net/mlx5e: Move dynamic interrupt coalescing code to include/linux")
Fixes: cb3c7fd4f8 ("net/mlx5e: Support adaptive RX coalescing")
Signed-off-by: Roy Novich <royno@nvidia.com>
Reviewed-by: Aya Levin <ayal@nvidia.com>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
Link: https://lore.kernel.org/r/20230507135743.138993-1-tariqt@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
110 lines
2.6 KiB
C
110 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
|
|
/*
|
|
* Copyright (c) 2019, Mellanox Technologies inc. All rights reserved.
|
|
*/
|
|
|
|
#include <linux/dim.h>
|
|
|
|
static int rdma_dim_step(struct dim *dim)
|
|
{
|
|
if (dim->tune_state == DIM_GOING_RIGHT) {
|
|
if (dim->profile_ix == (RDMA_DIM_PARAMS_NUM_PROFILES - 1))
|
|
return DIM_ON_EDGE;
|
|
dim->profile_ix++;
|
|
dim->steps_right++;
|
|
}
|
|
if (dim->tune_state == DIM_GOING_LEFT) {
|
|
if (dim->profile_ix == 0)
|
|
return DIM_ON_EDGE;
|
|
dim->profile_ix--;
|
|
dim->steps_left++;
|
|
}
|
|
|
|
return DIM_STEPPED;
|
|
}
|
|
|
|
static int rdma_dim_stats_compare(struct dim_stats *curr,
|
|
struct dim_stats *prev)
|
|
{
|
|
/* first stat */
|
|
if (!prev->cpms)
|
|
return DIM_STATS_SAME;
|
|
|
|
if (IS_SIGNIFICANT_DIFF(curr->cpms, prev->cpms))
|
|
return (curr->cpms > prev->cpms) ? DIM_STATS_BETTER :
|
|
DIM_STATS_WORSE;
|
|
|
|
if (IS_SIGNIFICANT_DIFF(curr->cpe_ratio, prev->cpe_ratio))
|
|
return (curr->cpe_ratio > prev->cpe_ratio) ? DIM_STATS_BETTER :
|
|
DIM_STATS_WORSE;
|
|
|
|
return DIM_STATS_SAME;
|
|
}
|
|
|
|
static bool rdma_dim_decision(struct dim_stats *curr_stats, struct dim *dim)
|
|
{
|
|
int prev_ix = dim->profile_ix;
|
|
u8 state = dim->tune_state;
|
|
int stats_res;
|
|
int step_res;
|
|
|
|
if (state != DIM_PARKING_ON_TOP && state != DIM_PARKING_TIRED) {
|
|
stats_res = rdma_dim_stats_compare(curr_stats,
|
|
&dim->prev_stats);
|
|
|
|
switch (stats_res) {
|
|
case DIM_STATS_SAME:
|
|
if (curr_stats->cpe_ratio <= 50 * prev_ix)
|
|
dim->profile_ix = 0;
|
|
break;
|
|
case DIM_STATS_WORSE:
|
|
dim_turn(dim);
|
|
fallthrough;
|
|
case DIM_STATS_BETTER:
|
|
step_res = rdma_dim_step(dim);
|
|
if (step_res == DIM_ON_EDGE)
|
|
dim_turn(dim);
|
|
break;
|
|
}
|
|
}
|
|
|
|
dim->prev_stats = *curr_stats;
|
|
|
|
return dim->profile_ix != prev_ix;
|
|
}
|
|
|
|
void rdma_dim(struct dim *dim, u64 completions)
|
|
{
|
|
struct dim_sample *curr_sample = &dim->measuring_sample;
|
|
struct dim_stats curr_stats;
|
|
u32 nevents;
|
|
|
|
dim_update_sample_with_comps(curr_sample->event_ctr + 1, 0, 0,
|
|
curr_sample->comp_ctr + completions,
|
|
&dim->measuring_sample);
|
|
|
|
switch (dim->state) {
|
|
case DIM_MEASURE_IN_PROGRESS:
|
|
nevents = curr_sample->event_ctr - dim->start_sample.event_ctr;
|
|
if (nevents < DIM_NEVENTS)
|
|
break;
|
|
if (!dim_calc_stats(&dim->start_sample, curr_sample, &curr_stats))
|
|
break;
|
|
if (rdma_dim_decision(&curr_stats, dim)) {
|
|
dim->state = DIM_APPLY_NEW_PROFILE;
|
|
schedule_work(&dim->work);
|
|
break;
|
|
}
|
|
fallthrough;
|
|
case DIM_START_MEASURE:
|
|
dim->state = DIM_MEASURE_IN_PROGRESS;
|
|
dim_update_sample_with_comps(curr_sample->event_ctr, 0, 0,
|
|
curr_sample->comp_ctr,
|
|
&dim->start_sample);
|
|
break;
|
|
case DIM_APPLY_NEW_PROFILE:
|
|
break;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(rdma_dim);
|