Messages in this thread | | | Date | Tue, 21 Jun 2022 09:30:11 +0200 | Subject | Re: [PATCH] kbuild: pass jobserver to cmd_ld_vmlinux.o | From | Jiri Slaby <> |
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On 17. 06. 22, 18:32, Nick Desaulniers wrote: > On Fri, Jun 17, 2022 at 3:35 AM Sedat Dilek <sedat.dilek@gmail.com> wrote: >> >> On Fri, Jun 17, 2022 at 12:53 AM Sedat Dilek <sedat.dilek@gmail.com> wrote: >>> >>> On Thu, Jun 16, 2022 at 4:09 PM Sedat Dilek <sedat.dilek@gmail.com> wrote: >>>> >>>> On Thu, Jun 16, 2022 at 12:45 PM Jiri Slaby <jslaby@suse.cz> wrote: >>>>> >>>>> Until the link-vmlinux.sh split (cf. the commit below), the linker was >>>>> run with jobserver set in MAKEFLAGS. After the split, the command in >>>>> Makefile.vmlinux_o is not prefixed by "+" anymore, so this information >>>>> is lost. >>>>> >>>>> Restore it as linkers working in parallel (esp. the LTO ones) make a use >>>>> of it. > > TBH, I agree with Masahiro. I didn't understand this comment "esp. the > LTO ones." Jiri, can you clarify what you mean here?
Sure. clang is not the only compiler/linker that can handle kernel ;). So while rebasing gcc-LTO-kernel-patches to 5.19-rc (to upstream them later), this broke. See: https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/lto-wrapper.cc;h=26e06e77be4e0afb2bc3e913062a9c51cab5d205;hb=HEAD#l1336
gcc really parses MAKEFLAGS and looks for "--jobserver-auth=" there, if one passes specifies -flto=jobserver.
thanks, -- js suse labs
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