Re: [PATCH RFC 2/4] mm: percpu: Add pcpu_fc_cpu_to_node_fn_t typedef

[Kefeng Wang]

On 2021/11/30 6:40, Dennis Zhou wrote:
> On Sun, Nov 21, 2021 at 05:35:55PM +0800, Kefeng Wang wrote:
> > Add pcpu_fc_cpu_to_node_fn_t and pass it into pcpu_fc_alloc_fn_t,
> > pcpu first chunk allocation will call it to alloc memblock on the
> > corresponding node by it.
> >
> > Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
> > ---
> >   arch/mips/mm/init.c            | 12 +++++++++---
> >   arch/powerpc/kernel/setup_64.c | 14 +++++++++++---
> >   arch/sparc/kernel/smp_64.c     |  8 +++++---
> >   arch/x86/kernel/setup_percpu.c | 18 +++++++++++++-----
> >   drivers/base/arch_numa.c       |  8 +++++---
> >   include/linux/percpu.h         |  7 +++++--
> >   mm/percpu.c                    | 14 +++++++++-----
> >   7 files changed, 57 insertions(+), 24 deletions(-)
> >
> > diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
...
> > diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
> > index 6052f5d5ded3..9a5609c821df 100644
> > --- a/arch/powerpc/kernel/setup_64.c
> > +++ b/arch/powerpc/kernel/setup_64.c
> > @@ -771,6 +771,12 @@ void __init emergency_stack_init(void)
> >   }
> >   
> >   #ifdef CONFIG_SMP
> > +
> > +static __init int pcpu_cpu_to_node(int cpu)
> > +{
> > +	return IS_ENABLED(CONFIG_NUMA) ? early_cpu_to_node(cpu) : NUMA_NO_NODE;
> > +}
> > +
> >   /**
> >    * pcpu_alloc_bootmem - NUMA friendly alloc_bootmem wrapper for percpu
> >    * @cpu: cpu to allocate for
> > @@ -784,12 +790,12 @@ void __init emergency_stack_init(void)
> >    * RETURNS:
> >    * Pointer to the allocated area on success, NULL on failure.
> >    */
> > -static void * __init pcpu_alloc_bootmem(unsigned int cpu, size_t size,
> > -					size_t align)
> > +static void * __init pcpu_alloc_bootmem(unsigned int cpu, size_t size, size_t align,
> > +					pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn)
> >   {
> >   	const unsigned long goal = __pa(MAX_DMA_ADDRESS);
> >   #ifdef CONFIG_NUMA
> > -	int node = early_cpu_to_node(cpu);
> > +	int node = cpu_to_nd_fun(cpu);
> ^ typo - cpu_to_nd_fn().

Will fix.

...

> >   	if (rc < 0)
> > diff --git a/include/linux/percpu.h b/include/linux/percpu.h
> > index ae4004e7957e..41bb54715b0c 100644
> > --- a/include/linux/percpu.h
> > +++ b/include/linux/percpu.h
> > @@ -94,8 +94,9 @@ extern const char * const pcpu_fc_names[PCPU_FC_NR];
> >   
> >   extern enum pcpu_fc pcpu_chosen_fc;
> >   
> > -typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
> > -				     size_t align);
> > +typedef int (pcpu_fc_cpu_to_node_fn_t)(int cpu);
> > +typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size, size_t align,
> > +				     pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn);
> >   typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
> >   typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
> >   typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
> > @@ -111,6 +112,7 @@ extern void __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
> >   extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
> >   				size_t atom_size,
> >   				pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
> > +				pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn,
> >   				pcpu_fc_alloc_fn_t alloc_fn,
> >   				pcpu_fc_free_fn_t free_fn);
> >   #endif
> > @@ -119,6 +121,7 @@ extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
> >   extern int __init pcpu_page_first_chunk(size_t reserved_size,
> >   				pcpu_fc_alloc_fn_t alloc_fn,
> >   				pcpu_fc_free_fn_t free_fn,
> > +				pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn,
> >   				pcpu_fc_populate_pte_fn_t populate_pte_fn);
> >   #endif
> Be consistent here. In pcpu_setup_first_chunk() you add the
> cpu_to_node() before alloc()/free() and then in pcpu_embed_first_chunk()
> you add it after. I'd prefer to add it before as to keep the
> cpu_distance()/cpu_to_node() grouping.
Sure, will adjust the order.