Messages in this thread | ![/](/images/icornerl.gif) | | Date | Thu, 15 Jun 2023 06:54:33 -0700 (PDT) | Subject | Re: [PATCH v2 0/4] riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION | From | Palmer Dabbelt <> |
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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.
> > Thanks
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