Messages in this thread | | | From | Guo Ren <> | Date | Fri, 4 Aug 2023 08:53:12 +0800 | Subject | Re: [RFC PATCH v2 0/3] Deduplicate RISCV cmpxchg.h and atomic.c macros |
| |
On Thu, Aug 3, 2023 at 1:14 PM Leonardo Bras <leobras@redhat.com> wrote: > > I unified previous patchsets into a single one, since the work is related. > > While studying riscv's cmpxchg.h file, I got really interested in > understanding how RISCV asm implemented the different versions of > {cmp,}xchg. > > When I understood the pattern, it made sense for me to remove the > duplications and create macros to make it easier to understand what exactly > changes between the versions: Instruction sufixes & barriers. > > Also, did the same kind of work on atomic.c. > > Note to Guo Ren: > I did some further improvement after your previous reviews, so I ended > up afraid including your Reviewed-by before cheching if the changes are > ok for you. Please check it out again, I just removed some helper macros > that were not being used elsewhere in the kernel. I found this optimization has conflicts with the below patches: https://lore.kernel.org/linux-riscv/20230802164701.192791-15-guoren@kernel.org/ https://lore.kernel.org/linux-riscv/20230802164701.192791-5-guoren@kernel.org/
If yours merged, how do we support the inline cmpxchg/xchg_small function? It's very struggling to use macros to implement complex functions.
Could you consider a more relaxed optimization in which we could insert inline cmpxchg/xchg_small?
> > Thanks! > Leo > > > Changes since squashed cmpxchg: > - Unified with atomic.c patchset > - Rebased on top of torvalds/master (thanks Andrea Parri!) > - Removed helper macros that were not being used elsewhere in the kernel. > > Changes since (cmpxchg) RFCv3: > - Squashed the 6 original patches in 2: one for cmpxchg and one for xchg > https://lore.kernel.org/all/20230404163741.2762165-1-leobras@redhat.com/ > > Changes since (cmpxchg) RFCv2: > - Fixed macros that depend on having a local variable with a magic name > - Previous cast to (long) is now only applied on 4-bytes cmpxchg > https://lore.kernel.org/all/20230321074249.2221674-1-leobras@redhat.com/ > > Changes since (cmpxchg) RFCv1: > - Fixed patch 4/6 suffix from 'w.aqrl' to '.w.aqrl', to avoid build error > https://lore.kernel.org/all/20230318080059.1109286-1-leobras@redhat.com/ > > > Leonardo Bras (3): > riscv/cmpxchg: Deduplicate xchg() asm functions > riscv/cmpxchg: Deduplicate cmpxchg() asm and macros > riscv/atomic.h : Deduplicate arch_atomic.* > > arch/riscv/include/asm/atomic.h | 164 ++++++++-------- > arch/riscv/include/asm/cmpxchg.h | 318 +++++-------------------------- > 2 files changed, 123 insertions(+), 359 deletions(-) > > -- > 2.41.0 >
-- Best Regards Guo Ren
| |