Messages in this thread | | | Date | Mon, 19 Jun 2023 15:06:30 -0700 (PDT) | Subject | Re: [PATCH v2 0/4] riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION | From | Palmer Dabbelt <> |
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On Thu, 15 Jun 2023 06:54:33 PDT (-0700), Palmer Dabbelt wrote: > On Wed, 14 Jun 2023 09:25:49 PDT (-0700), jszhang@kernel.org wrote: >> >> On Wed, Jun 14, 2023 at 07:49:17AM -0700, Palmer Dabbelt wrote: >>> On Tue, 23 May 2023 09:54:58 PDT (-0700), jszhang@kernel.org wrote: >>> > When trying to run linux with various opensource riscv core on >>> > resource limited FPGA platforms, for example, those FPGAs with less >>> > than 16MB SDRAM, I want to save mem as much as possible. One of the >>> > major technologies is kernel size optimizations, I found that riscv >>> > does not currently support HAVE_LD_DEAD_CODE_DATA_ELIMINATION, which >>> > passes -fdata-sections, -ffunction-sections to CFLAGS and passes the >>> > --gc-sections flag to the linker. >>> > >>> > This not only benefits my case on FPGA but also benefits defconfigs. >>> > Here are some notable improvements from enabling this with defconfigs: >>> > >>> > nommu_k210_defconfig: >>> > text data bss dec hex >>> > 1112009 410288 59837 1582134 182436 before >>> > 962838 376656 51285 1390779 1538bb after >>> > >>> > rv32_defconfig: >>> > text data bss dec hex >>> > 8804455 2816544 290577 11911576 b5c198 before >>> > 8692295 2779872 288977 11761144 b375f8 after >>> > >>> > defconfig: >>> > text data bss dec hex >>> > 9438267 3391332 485333 13314932 cb2b74 before >>> > 9285914 3350052 483349 13119315 c82f53 after >>> > >>> > patch1 and patch2 are clean ups. >>> > patch3 fixes a typo. >>> > patch4 finally enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION for riscv. >>> > >>> > NOTE: Zhangjin Wu firstly sent out a patch to enable dead code >>> > elimination for riscv several months ago, I didn't notice it until >>> > yesterday. Although it missed some preparations and some sections's >>> > keeping, he is the first person to enable this feature for riscv. To >>> > ease merging, this series take his patch into my entire series and >>> > makes patch4 authored by him after getting his ack to reflect >>> > the above fact. >>> > >>> > Since v1: >>> > - collect Reviewed-by, Tested-by tag >>> > - Make patch4 authored by Zhangjin Wu, add my co-developed-by tag >>> > >>> > Jisheng Zhang (3): >>> > riscv: move options to keep entries sorted >>> > riscv: vmlinux-xip.lds.S: remove .alternative section >>> > vmlinux.lds.h: use correct .init.data.* section name >>> > >>> > Zhangjin Wu (1): >>> > riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION >>> > >>> > arch/riscv/Kconfig | 13 +- >>> > arch/riscv/kernel/vmlinux-xip.lds.S | 6 - >>> > arch/riscv/kernel/vmlinux.lds.S | 6 +- >>> > include/asm-generic/vmlinux.lds.h | 2 +- >>> > 4 files changed, 11 insertions(+), 16 deletions(-) >>> >>> Do you have a base commit for this? It's not applying to 6.4-rc1 and the >>> patchwork bot couldn't find one either. >> >> Hi Palmer, >> >> Commit 3b90b09af5be ("riscv: Fix orphan section warnings caused by >> kernel/pi") touches vmlinux.lds.S, so to make the merge easy, this >> series is based on 6.4-rc2. > > Thanks.
Sorry to be so slow here, but I think this is causing LLD to hang on allmodconfig. I'm still getting to the bottom of it, there's a few other things I have in flight still.
> >> >> Thanks
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