paulkirth added a comment. In D135488#4048380 <https://reviews.llvm.org/D135488#4048380>, @nickdesaulniers wrote:
> It would be really nice if we could limit this to a specific function somehow. I think you can do that, right ? see: https://llvm.org/docs/Remarks.html#cmdoption-pass-remarks-filter https://llvm.org/docs/Remarks.html#cmdoption-pass-remarks-filter > Quick feedback from giving Diff 488727 a spin on the Linux kernel: > > via `ARCH=arm make LLVM=1 -j128 -s allyesconfig all` I found: > > CC drivers/net/ethernet/mellanox/mlx5/core/en_main.o > drivers/net/ethernet/mellanox/mlx5/core/en_main.c:3597:12: error: stack > frame size (1256) exceeds limit (1024) in 'mlx5e_setup_tc' > [-Werror,-Wframe-larger-than] > static int mlx5e_setup_tc(struct net_device *dev, enum tc_setup_type type, > ^ > > When I rebuild with: > > ARCH=arm make LLVM=1 -j128 > drivers/net/ethernet/mellanox/mlx5/core/en_main.o > KCFLAGS=-Rpass-analysis=stack-frame-layout > > I get a printout of the stack usage of every function in this TU. That's 1929 > lines of text output...I only care about `mlx5e_setup_tc`. Is there a way to > limit that? see: https://llvm.org/docs/Remarks.html#cmdoption-pass-remarks-filter If that doesn't sort you out, we can probably do //something// about this. In the worst case we'd need to make this a bigger pass, and also emit diagnostics for stack size, etc instead of in prologue/epilogue inserter. That was mentioned earlier, but I think that should be a separate change. > Filtering through the logs though, I do see: > > drivers/net/ethernet/mellanox/mlx5/core/en_main.c:3599:1: remark: > Function: mlx5e_setup_tc > ... > Offset: [SP-400], Type: Variable, Align: 8, Size: 352 > Offset: [SP-752], Type: Variable, Align: 8, Size: 352 > Offset: [SP-1088], Type: Variable, Align: 8, Size: 336 > > which is good! If I flip on debug info and rebuild, this looks like: > > drivers/net/ethernet/mellanox/mlx5/core/en_main.c:3599:1: remark: > Function: mlx5e_setup_tc > ... > Offset: [SP-400], Type: Variable, Align: 8, Size: 352 > old_params @ drivers/net/ethernet/mellanox/mlx5/core/en_main.c:2934 > old_chs @ drivers/net/ethernet/mellanox/mlx5/core/en_main.c:2958 > new_params @ drivers/net/ethernet/mellanox/mlx5/core/en_main.c:3539 > Offset: [SP-752], Type: Variable, Align: 8, Size: 352 > new_chs @ drivers/net/ethernet/mellanox/mlx5/core/en_main.c:3000 > Offset: [SP-1088], Type: Variable, Align: 8, Size: 336 > new_params @ drivers/net/ethernet/mellanox/mlx5/core/en_main.c:3424 > > Which is pretty awesome! > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/ethernet/mellanox/mlx5/core/en_main.c#n3424 > for the last one, which shows we should probably be heap allocating > instances of `struct mlx5e_params` rather than stack allocating them! > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/ethernet/mellanox/mlx5/core/en_main.c#n3000 > shows the same for `struct mlx5e_channels`. Cool stuff! Now we can finally > debug `-Wframe-larger-than=`!!! Glad this helps! If you think of more issues, let me know. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D135488/new/ https://reviews.llvm.org/D135488 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
