On Fri, Nov 02, 2018 at 04:33:03PM +0100, Arnd Bergmann wrote: > A patch that looks harmless causes the stack usage of the mlx5e_grp_sw_update_stats() > function to drastically increase with x86 gcc-4.9 and higher (tested up to 8.1): > > 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:216:1: warning: the frame size of 1276 bytes is larger than 500 bytes [-Wframe-larger-than=] Why is the stack size so big here? The mlx5e_sw_stats is < 500 bytes and all the other on-stack stuff looks pretty small? > By splitting out the loop body into a non-inlined function, the stack size goes > back down to under 500 bytes. Does this actually reduce the stack consumed or does this just suppress the warning? Jason
