Re: [PATCH] mlx5: work around high stack usage with gcc

From: Saeed Mahameed
Date: Mon Jan 06 2020 - 16:59:37 EST


On Mon, 2020-01-06 at 13:34 -0800, David Miller wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
> Date: Sat, 4 Jan 2020 22:51:44 +0100
>
> > In some configurations, gcc tries too hard to optimize this code:
> >
> > drivers/net/ethernet/mellanox/mlx5/core/en_stats.c: In function
> 'mlx5e_grp_sw_update_stats':
> > drivers/net/ethernet/mellanox/mlx5/core/en_stats.c:302:1: error:
> the frame size of 1336 bytes is larger than 1024 bytes [-
> Werror=frame-larger-than=]
> >
> > As was stated in the bug report, the reason is that gcc runs into a
> corner
> > case in the register allocator that is rather hard to fix in a good
> way.
> >
> > As there is an easy way to work around it, just add a comment and
> the
> > barrier that stops gcc from trying to overoptimize the function.
> >
> > Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92657
> > Cc: Adhemerval Zanella <adhemerval.zanella@xxxxxxxxxx>
> > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
>
> Saeed, please take this.
>
> Thank you.
>

Applied to net-next-mlx5

will submit to net-next later today.

Thanks !