Messages in this thread | | | From | Sami Tolvanen <> | Date | Tue, 18 Feb 2020 11:21:42 -0800 | Subject | Re: [PATCH] kbuild: remove duplicate dependencies from .mod files |
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Hi Masahiro,
On Sat, Feb 15, 2020 at 8:28 PM Masahiro Yamada <masahiroy@kernel.org> wrote: > masahiro@grover:~/workspace/linux-kbuild$ llvm-nm > drivers/gpu/drm/nouveau/nouveau.o | sed -n 's/^ *U //p' | sort -u | > wc > 572 572 11478
Thank you for testing this!
> Does ACK do this differently?
Yes, the difference is that we use LTO and after looking into this a bit more, it turns out that when the individual files in the thin archive are LLVM bitcode, llvm-nm behaves differently and prints out the symbols for each file separately.
$ llvm-nm drivers/gpu/drm/nouveau/nouveau.o ... nvif/client.o: ---------------- W __cfi_check ---------------- W __cfi_check_fail U __cfi_slowpath_diag U __ubsan_handle_cfi_check_fail ---------------- T nvif_client_fini ---------------- T nvif_client_init ---------------- T nvif_client_ioctl ---------------- T nvif_client_resume ---------------- T nvif_client_suspend U nvif_object_fini U nvif_object_init U strncpy
nvif/device.o: ---------------- W __cfi_check ---------------- W __cfi_check_fail U __ubsan_handle_cfi_check_fail U kfree ---------------- T nvif_device_fini ---------------- T nvif_device_init ---------------- T nvif_device_time U nvif_object_fini U nvif_object_init U nvif_object_mthd U nvif_user_fini ...
While this output format still works for us, it does generate a lot of duplicates. Anyway, I think we can come back to this when LTO is closer to getting upstreamed.
Sami
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