Re: [PATCH v1 5/5] hv_balloon: try to merge system ram resources

[Wei Liu]

On Fri, Aug 21, 2020 at 12:34:31PM +0200, David Hildenbrand wrote:
> Let's use the new mechanism to merge system ram resources below the
> root. We are the only one hotplugging system ram, e.g., DIMMs don't apply,
> so this is safe to be used.
> 
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Michal Hocko <mhocko@xxxxxxxx>
> Cc: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx>
> Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> Cc: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
> Cc: Wei Liu <wei.liu@xxxxxxxxxx>
> Cc: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx>
> Cc: Baoquan He <bhe@xxxxxxxxxx>
> Cc: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
> ---
>  drivers/hv/hv_balloon.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
> index 32e3bc0aa665a..49a6305f0fb73 100644
> --- a/drivers/hv/hv_balloon.c
> +++ b/drivers/hv/hv_balloon.c
> @@ -745,6 +745,9 @@ static void hv_mem_hot_add(unsigned long start, unsigned long size,
>  			has->covered_end_pfn -=  processed_pfn;
>  			spin_unlock_irqrestore(&dm_device.ha_lock, flags);
>  			break;
> +		} else {
> +			/* Try to reduce the number of system ram resources. */
> +			merge_system_ram_resources(&iomem_resource);
>  		}

You don't need to put the call under the "else" branch. It will have
broken out of the loop if ret is not zero.

Wei.

>  
>  		/*
> -- 
> 2.26.2
>