Messages in this thread |  | | Date | Thu, 10 Apr 2025 19:28:18 +0200 | | From | Michal Kubiak <> | | Subject | Re: [PATCH net-next 11/12] net/mlx5: HWS, Free unused action STE tables |
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On Tue, Apr 08, 2025 at 05:00:55PM +0300, Tariq Toukan wrote: > From: Vlad Dogaru <vdogaru@nvidia.com> > > Periodically check for unused action STE tables and free their > associated resources. In order to do this safely, add a per-queue lock > to synchronize the garbage collect work with regular operations on > steering rules. > > Signed-off-by: Vlad Dogaru <vdogaru@nvidia.com> > Reviewed-by: Yevgeny Kliteynik <kliteyn@nvidia.com> > Reviewed-by: Mark Bloch <mbloch@nvidia.com> > Signed-off-by: Tariq Toukan <tariqt@nvidia.com> > --- > .../mlx5/core/steering/hws/action_ste_pool.c | 88 ++++++++++++++++++- > .../mlx5/core/steering/hws/action_ste_pool.h | 11 +++ > .../mellanox/mlx5/core/steering/hws/context.h | 1 + > 3 files changed, 96 insertions(+), 4 deletions(-)
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> + > +static void hws_action_ste_pool_cleanup(struct work_struct *work) > +{ > + enum mlx5hws_pool_optimize opt; > + struct mlx5hws_context *ctx; > + LIST_HEAD(cleanup); > + int i; > + > + ctx = container_of(work, struct mlx5hws_context, > + action_ste_cleanup.work); > + > + for (i = 0; i < ctx->queues; i++) { > + struct mlx5hws_action_ste_pool *p = &ctx->action_ste_pool[i]; > + > + mutex_lock(&p->lock); > + for (opt = MLX5HWS_POOL_OPTIMIZE_NONE; > + opt < MLX5HWS_POOL_OPTIMIZE_MAX; opt++) > + hws_action_ste_pool_element_collect_stale( > + &p->elems[opt], &cleanup); > + mutex_unlock(&p->lock); > + }
As I understand, in the loop above all unused items are being collected to remove them at the end of the function, using `hws_action_ste_table_cleanup_list()`.
I noticed that only the collecting of elements is protected with the mutex. So I have a question: is it possible that in a very short period of time (between `mutex_unlock()` and `hws_action_ste_table_cleanup_list()` calls), the cleanup list can somehow be invalidated (by changing the STE state in another thread)?
> + > + hws_action_ste_table_cleanup_list(&cleanup); > + > + schedule_delayed_work(&ctx->action_ste_cleanup, > + secs_to_jiffies( > + MLX5HWS_ACTION_STE_POOL_CLEANUP_SECONDS)); > +} > +
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Thanks, Michal
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