Ping: [PATCH] mem-sharing: move (x86) / drop (Arm) arch_dump_shared_mem_info()

[Jan Beulich <jbeulich@xxxxxxxx>]

On 08.08.2023 14:02, Jan Beulich wrote:
> When !MEM_SHARING no useful output is produced. Move the function into
> mm/mem_sharing.c while conditionalizing the call to it, thus allowing to
> drop it altogether from Arm (and eliminating the need to introduce stubs
> on PPC and RISC-V).
> 
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

Tamas - any chance of an ack?

Thanks, Jan

> ---
> I wasn't really sure whether introducing a stub in xen/mm.h would be any
> better than adding the (further) #ifdef to dump_domains().
> 
> We could go further and also eliminate the need for the stub variants
> of mem_sharing_get_nr_{shared,saved}_mfns() by moving the
> XENMEM_get_sharing_{shared,freed}_pages cases in
> {,compat_}arch_memory_op() into the already existing #ifdef-s there.
> Returning an error for those sub-ops may be slightly more appropriate
> than returning 0 when !MEM_SHARING.
> 
> --- a/xen/arch/arm/mm.c
> +++ b/xen/arch/arm/mm.c
> @@ -1297,10 +1297,6 @@ void free_init_memory(void)
>      printk("Freed %ldkB init memory.\n", 
> (long)(__init_end-__init_begin)>>10);
>  }
>  
> -void arch_dump_shared_mem_info(void)
> -{
> -}
> -
>  int steal_page(
>      struct domain *d, struct page_info *page, unsigned int memflags)
>  {
> --- a/xen/arch/x86/mm.c
> +++ b/xen/arch/x86/mm.c
> @@ -6265,13 +6265,6 @@ void memguard_unguard_stack(void *p)
>      map_pages_to_xen((unsigned long)p, virt_to_mfn(p), 1, 
> PAGE_HYPERVISOR_RW);
>  }
>  
> -void arch_dump_shared_mem_info(void)
> -{
> -    printk("Shared frames %u -- Saved frames %u\n",
> -            mem_sharing_get_nr_shared_mfns(),
> -            mem_sharing_get_nr_saved_mfns());
> -}
> -
>  const struct platform_bad_page *__init get_platform_badpages(unsigned int 
> *array_size)
>  {
>      u32 igd_id;
> --- a/xen/arch/x86/mm/mem_sharing.c
> +++ b/xen/arch/x86/mm/mem_sharing.c
> @@ -2329,3 +2329,10 @@ int mem_sharing_domctl(struct domain *d,
>  
>      return rc;
>  }
> +
> +void arch_dump_shared_mem_info(void)
> +{
> +    printk("Shared frames %u -- Saved frames %u\n",
> +            mem_sharing_get_nr_shared_mfns(),
> +            mem_sharing_get_nr_saved_mfns());
> +}
> --- a/xen/common/keyhandler.c
> +++ b/xen/common/keyhandler.c
> @@ -365,7 +365,9 @@ static void cf_check dump_domains(unsign
>          }
>      }
>  
> +#ifdef CONFIG_MEM_SHARING
>      arch_dump_shared_mem_info();
> +#endif
>  
>      rcu_read_unlock(&domlist_read_lock);
>  }
>