Re: [PATCH dwarves 0/2] dwarf_loader: improve cus__merging_cu()

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Tue, Apr 06, 2021 at 02:07:26PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Tue, Apr 06, 2021 at 02:03:41PM -0300, Arnaldo Carvalho de Melo escreveu:
> > Sorry, I forgot to use clang on this no-lto build... doing it now with:
> > 
> > [acme@five bpf]$ grep LTO ../build/bpf_clang_no_lto/.config
> > CONFIG_ARCH_SUPPORTS_LTO_CLANG=y
> > CONFIG_ARCH_SUPPORTS_LTO_CLANG_THIN=y
> > CONFIG_HAS_LTO_CLANG=y
> > CONFIG_LTO_NONE=y
> > # CONFIG_LTO_CLANG_FULL is not set
> > # CONFIG_LTO_CLANG_THIN is not set
> > CONFIG_HID_WALTOP=m
> > [acme@five bpf]$
> > [acme@five bpf]$ make -j28 LLVM=1 LLVM_IAS=1 O=../build/bpf_clang_no_lto/ vmlinux
> 
> 
> Works:
> 
> [acme@five bpf]$ make -j28 LLVM=1 LLVM_IAS=1 O=../build/bpf_clang_no_lto/ vmlinux


Now with FULL LTO:

  CC      fs/mbcache.o
  CC      fs/posix_acl.o
  CC      fs/coredump.o
  CC      fs/drop_caches.o
  CC      fs/fhandle.o
  AR      drivers/soundwire/built-in.a
  AR      drivers/hid/built-in.a
  AR      drivers/acpi/built-in.a
  AR      drivers/built-in.a
  AR      fs/built-in.a
  GEN     .version
  CHK     include/generated/compile.h
  GEN     .tmp_initcalls.lds
  LTO     vmlinux.o
  OBJTOOL vmlinux.o
vmlinux.o: warning: objtool: aesni_gcm_init_avx_gen2()+0x12: unsupported stack pointer realignment
vmlinux.o: warning: objtool: aesni_gcm_enc_update_avx_gen2()+0x12: unsupported stack pointer realignment
vmlinux.o: warning: objtool: aesni_gcm_dec_update_avx_gen2()+0x12: unsupported stack pointer realignment
vmlinux.o: warning: objtool: aesni_gcm_finalize_avx_gen2()+0x12: unsupported stack pointer realignment
vmlinux.o: warning: objtool: aesni_gcm_init_avx_gen4()+0x12: unsupported stack pointer realignment
vmlinux.o: warning: objtool: aesni_gcm_enc_update_avx_gen4()+0x12: unsupported stack pointer realignment
vmlinux.o: warning: objtool: aesni_gcm_dec_update_avx_gen4()+0x12: unsupported stack pointer realignment
vmlinux.o: warning: objtool: aesni_gcm_finalize_avx_gen4()+0x12: unsupported stack pointer realignment
  MODPOST vmlinux.symvers
  MODINFO modules.builtin.modinfo
  GEN     modules.builtin
  LD      .tmp_vmlinux.btf

  BTF     .btf.vmlinux.bin.o
  LD      .tmp_vmlinux.kallsyms1
  KSYMS   .tmp_vmlinux.kallsyms1.S
  AS      .tmp_vmlinux.kallsyms1.S
  LD      .tmp_vmlinux.kallsyms2
  KSYMS   .tmp_vmlinux.kallsyms2.S
  AS      .tmp_vmlinux.kallsyms2.S
  LD      vmlinux
  BTFIDS  vmlinux
  SORTTAB vmlinux
  SYSMAP  System.map
make[1]: Leaving directory '/home/acme/git/build/bpf_clang_full_lto'

real	8m36.854s
user	50m44.832s
sys	4m0.946s
[acme@five bpf]$

[acme@five bpf]$ cat /etc/fedora-release
Fedora release 33 (Thirty Three)
[acme@five bpf]$ grep LTO ../build/bpf_clang_full_lto/.config
CONFIG_LTO=y
CONFIG_LTO_CLANG=y
CONFIG_ARCH_SUPPORTS_LTO_CLANG=y
CONFIG_ARCH_SUPPORTS_LTO_CLANG_THIN=y
CONFIG_HAS_LTO_CLANG=y
# CONFIG_LTO_NONE is not set
CONFIG_LTO_CLANG_FULL=y
# CONFIG_LTO_CLANG_THIN is not set
CONFIG_HID_WALTOP=m
[acme@five bpf]$


Probably this will go away if I update clang/llvm? :)

Will try.

- Arnaldo