On Tue, 12 Sep 2023 09:37:00 +0100
Adrián Larumbe <adrian.larumbe@xxxxxxxxxxxxx> wrote:
> The current implementation will try to pick the highest available size
> display unit as soon as the BO size exceeds that of the previous
> multiplier. That can lead to loss of precision in BO's whose size is
> not a multiple of a MiB.
>
> Fix it by changing the unit selection criteria.
>
> For much bigger BO's, their size will naturally be aligned on something
> bigger than a 4 KiB page, so in practice it is very unlikely their display
> unit would default to KiB.
Let's wait for Rob's opinion on this.
>
> Signed-off-by: Adrián Larumbe <adrian.larumbe@xxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/drm_file.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
> index 762965e3d503..bf7d2fe46bfa 100644
> --- a/drivers/gpu/drm/drm_file.c
> +++ b/drivers/gpu/drm/drm_file.c
> @@ -879,7 +879,7 @@ static void print_size(struct drm_printer *p, const char *stat,
> unsigned u;
>
> for (u = 0; u < ARRAY_SIZE(units) - 1; u++) {
> - if (sz < SZ_1K)
> + if (sz & (SZ_1K - 1))
> break;
> sz = div_u64(sz, SZ_1K);
> }
