ACK: [PATCH] [G/master] UBUNTU: packaging: arm64: introduce a 64KB mem pages flavour called 'generic-64k'

[Andrea Righi]

On Fri, Sep 18, 2020 at 04:07:11PM +0200, Paolo Pisati wrote:
> This patch introduces an arm64 64KB pages enabled flavour of the generic kernel,
> called 'generic-64k'.
> 
> Earlier benchmark with this config have shown an obvious trade-off:
> 
> 
> * Performance
> - comparing geometic mean of over 35 stress throughput tests we see
>     a bogo op throughput increase of 22.0-24.5% with 64K pages compared
>     to 4K pages.
> 
> * Memory usage:
>   - a simple check of memory used after boot shows that 64K pages uses
>     around 3.2-3.6x more memory. The amount of memory being shared also
>     increases by 15x more.
>   - a 32GB machine is seeing about 480MB more memory consumption, or
>     ~ 1.5% less free memory.
> 
> 
> In short, loss of memory because pages are larger but a large performance win
> because of less page table entry references and TLB misses: for machines with
> large memory, this flavour could make sense.
> 
> Since we are introducing an independent flavour, generic is not affected by this
> change.
> 
> Signed-off-by: Paolo Pisati <paolo.pisati at canonical.com>

Looks good to me.

Acked-by: Andrea Righi <andrea.righi at canonical.com>