Hi, > Am 09.09.2021 um 14:45 schrieb Zhou Yanjie <zhouyu@xxxxxxxxxxxxxx>: > > Hi, > > On 2021/9/8 下午8:41, Jiaxun Yang wrote: >> >> 在 2021/9/8 16:51, Thomas Bogendoerfer 写道: >>> On Wed, Sep 08, 2021 at 10:08:47AM +0800, 陈飞扬 wrote: >>>> On Tue, 7 Sept 2021 at 21:49, Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> wrote: >>>>> >>>>> 在 2021/9/7 14:16, FreeFlyingSheep 写道: >>>>>> From: Feiyang Chen <chenfeiyang@xxxxxxxxxxx> >>>>>> >>>>>> Convert mips syscall to use the generic entry infrastructure from >>>>>> kernel/entry/*. >>>>>> >>>>>> There are a few special things on mips: >>>>>> >>>>>> - There is one type of syscall on mips32 (scall32-o32) and three types >>>>>> of syscalls on mips64 (scall64-o32, scall64-n32 and scall64-n64). Now >>>>>> convert to C code to handle different types of syscalls. >>>>>> >>>>>> - For some special syscalls (e.g. fork, clone, clone3 and sysmips), >>>>>> save_static_function() wrapper is used to save static registers. Now >>>>>> SAVE_STATIC is used in handle_sys before calling do_syscall(), so the >>>>>> save_static_function() wrapper can be removed. >>>>>> >>>>>> - For sigreturn/rt_sigreturn and sysmips, inline assembly is used to >>>>>> jump to syscall_exit directly for skipping setting the error flag and >>>>>> restoring all registers. Now use regs->regs[27] to mark whether to >>>>>> handle the error flag and always restore all registers in handle_sys, >>>>>> so these functions can return normally as other architecture. >>>>> Hmm, that would give us overhead of register context on these syscalls. >>>>> >>>>> I guess it's worthy? >>>>> >>>> Hi, Jiaxun, >>>> >>>> Saving and restoring registers against different system calls can be >>>> difficult due to the use of generic entry. >>>> To avoid a lot of duplicate code, I think the overhead is worth it. >>> could you please provide numbers for that ? This code still runs >>> on low end MIPS CPUs for which overhead might mean a different >>> ballpark than some highend Loongson CPUs. >> >> It shows ~3% regression for UnixBench on MT7621A (1004Kec). >> >> + Yanjie could you help with a run on ingenic platform? > > > Sure, I can help with JZ4775, JZ4780, X1000, X1830, X2000 from Ingenic, and SF16A18, SF19A2890 from SiFlower. > > + Paul could you help with a run on JZ4760 and JZ4770? > > + Nikolaus could you help with a run on JZ4730? Have not observed a negative effect on jz4730. Same for jz4780. But I have not done performance tests. BR, Nikolaus
