Subject: Re: [EXTERNAL] Re: [PATCH V2 net-next] net: mana: Assigning IRQ affinity on HT cores

From: Jakub Kicinski <[email-masked]>
Date: Wed, 29 Nov 2023 16:02:02 -0800

On Wed, 29 Nov 2023 14:17:39 -0800 Souradeep Chakrabarti wrote:
> On Mon, Nov 27, 2023 at 10:06:39AM -0800, Jakub Kicinski wrote:
> > On Mon, 27 Nov 2023 09:36:38 +0000 Souradeep Chakrabarti wrote:  
> > > easier to keep things inside the mana driver code here  
> > 
> > Easier for who? Upstream we care about consistency and maintainability
> > across all drivers.  
> I am refactoring the code and putting some of the changes in topology.h
> and in nodemask.h. I am sharing the proposed change here for those two
> files. Please let me know if they are acceptable.

Thanks, adding Yury <[email-masked]> who's the best person 
to comment on the details...

> Added a new helper to iterate on numa nodes with cpu and start from a 
> particular node, instead of first node. This helps when we want to
> iterate from the local numa node.
> 
> diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
> index 8d07116caaf1..6e4528376164 100644
> --- a/include/linux/nodemask.h
> +++ b/include/linux/nodemask.h
> @@ -392,6 +392,15 @@ static inline void __nodes_fold(nodemask_t *dstp, const nodemask_t *origp,
>         for ((node) = 0; (node) < 1 && !nodes_empty(mask); (node)++)
>  #endif /* MAX_NUMNODES */
> 
> +#if MAX_NUMNODES > 1
> +#define for_each_node_next_mask(node_start, node_next, mask)           \
> +       for ((node_next) = (node_start);                                \
> +            (node_next) < MAX_NUMNODES;                                \
> +            (node_next) = next_node((node_next), (mask)))
> +#else
> +#define for_each_node_next_mask(node_start, node_next, mask)   \
> +       for_each_node_mask(node_next, mask)
> +#endif
>  /*
>   * Bitmasks that are kept for all the nodes.
>   */
> @@ -440,6 +449,8 @@ static inline int num_node_state(enum node_states state)
> 
>  #define for_each_node_state(__node, __state) \
>         for_each_node_mask((__node), node_states[__state])
> +#define for_each_node_next_state(__node_start, __node_next, __state) \
> +       for_each_node_next_mask((__node_start), (__node_next), node_states[__state])
> 
>  #define first_online_node      first_node(node_states[N_ONLINE])
>  #define first_memory_node      first_node(node_states[N_MEMORY])
> @@ -489,7 +500,8 @@ static inline int num_node_state(enum node_states state)
> 
>  #define for_each_node_state(node, __state) \
>         for ( (node) = 0; (node) == 0; (node) = 1)
> -
> +#define for_each_node_next_state(node, next_node, _state) \
> +       for_each_node_state(node, __state)
>  #define first_online_node      0
>  #define first_memory_node      0
>  #define next_online_node(nid)  (MAX_NUMNODES)
> @@ -535,6 +547,8 @@ static inline int node_random(const nodemask_t *maskp)
> 
>  #define for_each_node(node)       for_each_node_state(node, N_POSSIBLE)
>  #define for_each_online_node(node) for_each_node_state(node, N_ONLINE)
> +#define for_each_online_node_next(node, next_node)  \
> +                                 for_each_node_next_state(node, next_node, N_ONLINE)
> 
>  /*
>   * For nodemask scratch area.
> diff --git a/include/linux/topology.h b/include/linux/topology.h
> index 52f5850730b3..a06b16e5a955 100644
> --- a/include/linux/topology.h
> +++ b/include/linux/topology.h
> @@ -43,6 +43,9 @@
>         for_each_online_node(node)                      \
>                 if (nr_cpus_node(node))
> 
> +#define for_each_next_node_with_cpus(node, next_node)  \
> +               for_each_online_node_next(node, next_node)      \
> +               if (nr_cpus_node(next_node))
>  int arch_update_cpu_topology(void);
> 
>  /* Conform to ACPI 2.0 SLIT distance definitions */
>