ACK: [SRU][Bionic][PATCH 1/1] Revert "powerpc/powernv: Increase memory block size to 1GB on radix"

[Kleber Souza]

On 09/27/18 22:20, Joseph Salisbury wrote:
> From: Balbir Singh <bsingharora at gmail.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/1792102
> 
> This commit was a stop-gap to prevent crashes on hotunplug, caused by
> the mismatch between the 1G mappings used for the linear mapping and the
> memory block size. Those issues are now resolved because we split the
> linear mapping at hotunplug time if necessary, as implemented in commit
> 4dd5f8a99e79 ("powerpc/mm/radix: Split linear mapping on hot-unplug").
> 
> Signed-off-by: Balbir Singh <bsingharora at gmail.com>
> Signed-off-by: Michael Neuling <mikey at neuling.org>
> Tested-by: Rashmica Gupta <rashmica.g at gmail.com>
> Tested-by: Balbir Singh <bsingharora at gmail.com>
> Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
> (cherry picked from commit 7acf50e4efa60270edcb95107f660f5e258a90f2)
> Signed-off-by: Joseph Salisbury <joseph.salisbury at canonical.com>

Acked-by: Kleber Sacilotto de Souza <kleber.souza at canonical.com>

> ---
>  arch/powerpc/platforms/powernv/setup.c | 10 +---------
>  1 file changed, 1 insertion(+), 9 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
> index fc0412d..34e36f9 100644
> --- a/arch/powerpc/platforms/powernv/setup.c
> +++ b/arch/powerpc/platforms/powernv/setup.c
> @@ -362,15 +362,7 @@ static void pnv_kexec_cpu_down(int crash_shutdown, int secondary)
>  #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
>  static unsigned long pnv_memory_block_size(void)
>  {
> -	/*
> -	 * We map the kernel linear region with 1GB large pages on radix. For
> -	 * memory hot unplug to work our memory block size must be at least
> -	 * this size.
> -	 */
> -	if (radix_enabled())
> -		return 1UL * 1024 * 1024 * 1024;
> -	else
> -		return 256UL * 1024 * 1024;
> +	return 256UL * 1024 * 1024;
>  }
>  #endif
>  
>