@@ -69,22 +69,27 @@ void mlx5_cq_tasklet_cb(struct tasklet_struct *t)
static void mlx5_add_cq_to_tasklet(struct mlx5_core_cq *cq,
struct mlx5_eqe *eqe)
{
unsigned long flags;
struct mlx5_eq_tasklet *tasklet_ctx = cq->tasklet_ctx.priv;
+ bool schedule_tasklet = false;
spin_lock_irqsave(&tasklet_ctx->lock, flags);
/* When migrating CQs between EQs will be implemented, please note
* that you need to sync this point. It is possible that
* while migrating a CQ, completions on the old EQs could
* still arrive.
*/
if (list_empty_careful(&cq->tasklet_ctx.list)) {
mlx5_cq_hold(cq);
+ schedule_tasklet = list_empty(&tasklet_ctx->list);
list_add_tail(&cq->tasklet_ctx.list, &tasklet_ctx->list);
}
spin_unlock_irqrestore(&tasklet_ctx->lock, flags);
+
+ if (schedule_tasklet)
+ tasklet_schedule(&tasklet_ctx->task);
}
/* Callers must verify outbox status in case of err */
int mlx5_create_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq,
u32 *in, int inlen, u32 *out, int outlen)
@@ -112,17 +112,17 @@ static int mlx5_eq_comp_int(struct notifier_block *nb,
struct mlx5_eq_comp *eq_comp =
container_of(nb, struct mlx5_eq_comp, irq_nb);
struct mlx5_eq *eq = &eq_comp->core;
struct mlx5_eqe *eqe;
int num_eqes = 0;
- u32 cqn = -1;
eqe = next_eqe_sw(eq);
if (!eqe)
goto out;
do {
+ u32 cqn;
struct mlx5_core_cq *cq;
/* Make sure we read EQ entry contents after we've
* checked the ownership bit.
*/
@@ -145,13 +145,10 @@ static int mlx5_eq_comp_int(struct notifier_block *nb,
} while ((++num_eqes < MLX5_EQ_POLLING_BUDGET) && (eqe = next_eqe_sw(eq)));
out:
eq_update_ci(eq, 1);
- if (cqn != -1)
- tasklet_schedule(&eq_comp->tasklet_ctx.task);
-
return 0;
}
/* Some architectures don't latch interrupts when they are disabled, so using
* mlx5_eq_poll_irq_disabled could end up losing interrupts while trying to
Currently, the mlx5_eq_comp_int() interrupt handler schedules a tasklet to call mlx5_cq_tasklet_cb() if it processes any completions. For CQs whose completions don't need to be processed in tasklet context, this overhead is unnecessary. Atomic operations are needed to schedule, lock, and clear the tasklet. And when mlx5_cq_tasklet_cb() runs, it acquires a spin lock to access the list of CQs enqueued for processing. Schedule the tasklet in mlx5_add_cq_to_tasklet() instead to avoid this overhead. mlx5_add_cq_to_tasklet() is responsible for enqueuing the CQs to be processed in tasklet context, so it can schedule the tasklet. CQs that need tasklet processing have their interrupt comp handler set to mlx5_add_cq_to_tasklet(), so they will schedule the tasklet. CQs that don't need tasklet processing won't schedule the tasklet. To avoid scheduling the tasklet multiple times during the same interrupt, only schedule the tasklet in mlx5_add_cq_to_tasklet() if the tasklet work queue was empty before the new CQ was pushed to it. Note that the mlx4 driver works the same way: it schedules the tasklet in mlx4_add_cq_to_tasklet() and only if the work queue was empty before. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> --- drivers/net/ethernet/mellanox/mlx5/core/cq.c | 5 +++++ drivers/net/ethernet/mellanox/mlx5/core/eq.c | 5 +---- 2 files changed, 6 insertions(+), 4 deletions(-)