| Message ID | 20190529211340.17087-1-atish.patra@wdc.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Unify CPU topology across ARM & RISC-V | expand |
Hi, On 5/29/19 4:13 PM, Atish Patra wrote: > The cpu-map DT entry in ARM can describe the CPU topology in much better > way compared to other existing approaches. RISC-V can easily adopt this > binding to represent its own CPU topology. Thus, both cpu-map DT > binding and topology parsing code can be moved to a common location so > that RISC-V or any other architecture can leverage that. > > The relevant discussion regarding unifying cpu topology can be found in > [1]. > > arch_topology seems to be a perfect place to move the common code. I > have not introduced any significant functional changes in the moved code. > The only downside in this approach is that the capacity code will be > executed for RISC-V as well. But, it will exit immediately after not > able to find the appropriate DT node. If the overhead is considered too > much, we can always compile out capacity related functions under a > different config for the architectures that do not support them. > > There was an opportunity to unify topology data structure for ARM32 done > by patch 3/4. But, I refrained from making any other changes as I am not > very well versed with original intention for some functions that > are present in arch_topology.c. I hope this patch series can be served > as a baseline for such changes in the future. > > The patches have been tested for RISC-V and compile tested for ARM64, > ARM32 & x86. > I applied these to 5.2rc2, along with my PPTT/MT change and verified the system & scheduler topology/etc on DAWN and ThunderX2 using ACPI on arm64. They appear to be working correctly. so for the series, Tested-by: Jeremy Linton <jeremy.linton@arm.com> The code itself looks fine to me as well: Reviewed-by: Jeremy Linton <jeremy.linton@arm.com> Thanks! > The socket change[2] is also now part of this series. > > [1] https://lkml.org/lkml/2018/11/6/19 > [2] https://lkml.org/lkml/2018/11/7/918 > > QEMU changes for RISC-V topology are available at > > https://github.com/atishp04/qemu/tree/riscv_topology_dt > > HiFive Unleashed DT with topology node is available here. > https://github.com/atishp04/opensbi/tree/HiFive_unleashed_topology > > It can be verified with OpenSBI with following additional compile time > option. > > FW_PAYLOAD_FDT="unleashed_topology.dtb" > > Changes from v5->v6 > 1. Added two more patches from Sudeep about maintainership of arch_topology.c > and Kconfig update. > 2. Added Tested-by & Reviewed-by > 3. Fixed a nit (reordering of variables) > > Changes from v4-v5 > 1. Removed the arch_topology.h header inclusion from topology.c and arch_topology.c > file. Added it in linux/topology.h. > 2. core_id is set to -1 upon reset. Otherwise, ARM topology store function does not > work. > > Changes from v3->v4 > 1. Get rid of ARM32 specific information in topology structure. > 2. Remove redundant functions from ARM32 and use common code instead. > > Changes from v2->v3 > 1. Cover letter update with experiment DT for topology changes. > 2. Added the patch for [2]. > > Changes from v1->v2 > 1. ARM32 can now use the common code as well. > > Atish Patra (4): > dt-binding: cpu-topology: Move cpu-map to a common binding. > cpu-topology: Move cpu topology code to common code. > arm: Use common cpu_topology structure and functions. > RISC-V: Parse cpu topology during boot. > > Sudeep Holla (3): > Documentation: DT: arm: add support for sockets defining package > boundaries > base: arch_topology: update Kconfig help description > MAINTAINERS: Add an entry for generic architecture topology > > .../topology.txt => cpu/cpu-topology.txt} | 134 ++++++-- > MAINTAINERS | 7 + > arch/arm/include/asm/topology.h | 20 -- > arch/arm/kernel/topology.c | 60 +--- > arch/arm64/include/asm/topology.h | 23 -- > arch/arm64/kernel/topology.c | 303 +----------------- > arch/riscv/Kconfig | 1 + > arch/riscv/kernel/smpboot.c | 3 + > drivers/base/Kconfig | 2 +- > drivers/base/arch_topology.c | 298 +++++++++++++++++ > include/linux/arch_topology.h | 26 ++ > include/linux/topology.h | 1 + > 12 files changed, 452 insertions(+), 426 deletions(-) > rename Documentation/devicetree/bindings/{arm/topology.txt => cpu/cpu-topology.txt} (66%) > > -- > 2.21.0 >
On 5/30/19 2:12 PM, Jeremy Linton wrote: > Hi, > > On 5/29/19 4:13 PM, Atish Patra wrote: >> The cpu-map DT entry in ARM can describe the CPU topology in much better >> way compared to other existing approaches. RISC-V can easily adopt this >> binding to represent its own CPU topology. Thus, both cpu-map DT >> binding and topology parsing code can be moved to a common location so >> that RISC-V or any other architecture can leverage that. >> >> The relevant discussion regarding unifying cpu topology can be found in >> [1]. >> >> arch_topology seems to be a perfect place to move the common code. I >> have not introduced any significant functional changes in the moved code. >> The only downside in this approach is that the capacity code will be >> executed for RISC-V as well. But, it will exit immediately after not >> able to find the appropriate DT node. If the overhead is considered too >> much, we can always compile out capacity related functions under a >> different config for the architectures that do not support them. >> >> There was an opportunity to unify topology data structure for ARM32 done >> by patch 3/4. But, I refrained from making any other changes as I am not >> very well versed with original intention for some functions that >> are present in arch_topology.c. I hope this patch series can be served >> as a baseline for such changes in the future. >> >> The patches have been tested for RISC-V and compile tested for ARM64, >> ARM32 & x86. >> > > I applied these to 5.2rc2, along with my PPTT/MT change and verified the > system & scheduler topology/etc on DAWN and ThunderX2 using ACPI on > arm64. They appear to be working correctly. > > so for the series, > Tested-by: Jeremy Linton <jeremy.linton@arm.com> > > The code itself looks fine to me as well: > > Reviewed-by: Jeremy Linton <jeremy.linton@arm.com> > Thank you the review and testing on arm64 server. > Thanks! > >> The socket change[2] is also now part of this series. >> >> [1] https://lkml.org/lkml/2018/11/6/19 >> [2] https://lkml.org/lkml/2018/11/7/918 >> >> QEMU changes for RISC-V topology are available at >> >> https://github.com/atishp04/qemu/tree/riscv_topology_dt >> >> HiFive Unleashed DT with topology node is available here. >> https://github.com/atishp04/opensbi/tree/HiFive_unleashed_topology >> >> It can be verified with OpenSBI with following additional compile time >> option. >> >> FW_PAYLOAD_FDT="unleashed_topology.dtb" >> >> Changes from v5->v6 >> 1. Added two more patches from Sudeep about maintainership of arch_topology.c >> and Kconfig update. >> 2. Added Tested-by & Reviewed-by >> 3. Fixed a nit (reordering of variables) >> >> Changes from v4-v5 >> 1. Removed the arch_topology.h header inclusion from topology.c and arch_topology.c >> file. Added it in linux/topology.h. >> 2. core_id is set to -1 upon reset. Otherwise, ARM topology store function does not >> work. >> >> Changes from v3->v4 >> 1. Get rid of ARM32 specific information in topology structure. >> 2. Remove redundant functions from ARM32 and use common code instead. >> >> Changes from v2->v3 >> 1. Cover letter update with experiment DT for topology changes. >> 2. Added the patch for [2]. >> >> Changes from v1->v2 >> 1. ARM32 can now use the common code as well. >> >> Atish Patra (4): >> dt-binding: cpu-topology: Move cpu-map to a common binding. >> cpu-topology: Move cpu topology code to common code. >> arm: Use common cpu_topology structure and functions. >> RISC-V: Parse cpu topology during boot. >> >> Sudeep Holla (3): >> Documentation: DT: arm: add support for sockets defining package >> boundaries >> base: arch_topology: update Kconfig help description >> MAINTAINERS: Add an entry for generic architecture topology >> >> .../topology.txt => cpu/cpu-topology.txt} | 134 ++++++-- >> MAINTAINERS | 7 + >> arch/arm/include/asm/topology.h | 20 -- >> arch/arm/kernel/topology.c | 60 +--- >> arch/arm64/include/asm/topology.h | 23 -- >> arch/arm64/kernel/topology.c | 303 +----------------- >> arch/riscv/Kconfig | 1 + >> arch/riscv/kernel/smpboot.c | 3 + >> drivers/base/Kconfig | 2 +- >> drivers/base/arch_topology.c | 298 +++++++++++++++++ >> include/linux/arch_topology.h | 26 ++ >> include/linux/topology.h | 1 + >> 12 files changed, 452 insertions(+), 426 deletions(-) >> rename Documentation/devicetree/bindings/{arm/topology.txt => cpu/cpu-topology.txt} (66%) >> >> -- >> 2.21.0 >> > >
The cpu-map DT entry in ARM can describe the CPU topology in much better way compared to other existing approaches. RISC-V can easily adopt this binding to represent its own CPU topology. Thus, both cpu-map DT binding and topology parsing code can be moved to a common location so that RISC-V or any other architecture can leverage that. The relevant discussion regarding unifying cpu topology can be found in [1]. arch_topology seems to be a perfect place to move the common code. I have not introduced any significant functional changes in the moved code. The only downside in this approach is that the capacity code will be executed for RISC-V as well. But, it will exit immediately after not able to find the appropriate DT node. If the overhead is considered too much, we can always compile out capacity related functions under a different config for the architectures that do not support them. There was an opportunity to unify topology data structure for ARM32 done by patch 3/4. But, I refrained from making any other changes as I am not very well versed with original intention for some functions that are present in arch_topology.c. I hope this patch series can be served as a baseline for such changes in the future. The patches have been tested for RISC-V and compile tested for ARM64, ARM32 & x86. The socket change[2] is also now part of this series. [1] https://lkml.org/lkml/2018/11/6/19 [2] https://lkml.org/lkml/2018/11/7/918 QEMU changes for RISC-V topology are available at https://github.com/atishp04/qemu/tree/riscv_topology_dt HiFive Unleashed DT with topology node is available here. https://github.com/atishp04/opensbi/tree/HiFive_unleashed_topology It can be verified with OpenSBI with following additional compile time option. FW_PAYLOAD_FDT="unleashed_topology.dtb" Changes from v5->v6 1. Added two more patches from Sudeep about maintainership of arch_topology.c and Kconfig update. 2. Added Tested-by & Reviewed-by 3. Fixed a nit (reordering of variables) Changes from v4-v5 1. Removed the arch_topology.h header inclusion from topology.c and arch_topology.c file. Added it in linux/topology.h. 2. core_id is set to -1 upon reset. Otherwise, ARM topology store function does not work. Changes from v3->v4 1. Get rid of ARM32 specific information in topology structure. 2. Remove redundant functions from ARM32 and use common code instead. Changes from v2->v3 1. Cover letter update with experiment DT for topology changes. 2. Added the patch for [2]. Changes from v1->v2 1. ARM32 can now use the common code as well. Atish Patra (4): dt-binding: cpu-topology: Move cpu-map to a common binding. cpu-topology: Move cpu topology code to common code. arm: Use common cpu_topology structure and functions. RISC-V: Parse cpu topology during boot. Sudeep Holla (3): Documentation: DT: arm: add support for sockets defining package boundaries base: arch_topology: update Kconfig help description MAINTAINERS: Add an entry for generic architecture topology .../topology.txt => cpu/cpu-topology.txt} | 134 ++++++-- MAINTAINERS | 7 + arch/arm/include/asm/topology.h | 20 -- arch/arm/kernel/topology.c | 60 +--- arch/arm64/include/asm/topology.h | 23 -- arch/arm64/kernel/topology.c | 303 +----------------- arch/riscv/Kconfig | 1 + arch/riscv/kernel/smpboot.c | 3 + drivers/base/Kconfig | 2 +- drivers/base/arch_topology.c | 298 +++++++++++++++++ include/linux/arch_topology.h | 26 ++ include/linux/topology.h | 1 + 12 files changed, 452 insertions(+), 426 deletions(-) rename Documentation/devicetree/bindings/{arm/topology.txt => cpu/cpu-topology.txt} (66%) -- 2.21.0