| Message ID | 1543534100-3654-1-git-send-email-atish.patra@wdc.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Unify CPU topology across ARM64 & RISC-V | expand |
On 11/29/2018 4:28 PM, Atish Patra wrote: > The cpu-map DT entry in ARM64 can describe the CPU topology in > much better way compared to other existing approaches. RISC-V can > easily adopt this binding to represent it's 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 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. > > The patches have been tested for RISC-V and compile tested for > ARM64 & 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/riscv-qemu/tree/cpu_topo > > Apologies for the previous patch series with incorrect title and > was sent only to kernel mailing list due to a bug in my config. > Please ignore that. > > Atish Patra (3): > dt-binding: cpu-topology: Move cpu-map to a common binding. > cpu-topology: Move cpu topology code to common code. > RISC-V: Parse cpu topology during boot. > > Sudeep Holla (1): > Documentation: DT: arm: add support for sockets defining package > boundaries > > .../{arm/topology.txt => cpu/cpu-topology.txt} | 133 +++++++-- > arch/arm64/include/asm/topology.h | 22 -- > arch/arm64/kernel/topology.c | 303 +-------------------- > arch/riscv/Kconfig | 1 + > arch/riscv/kernel/smpboot.c | 3 + > drivers/base/arch_topology.c | 294 ++++++++++++++++++++ > include/linux/arch_topology.h | 26 ++ > include/linux/topology.h | 1 + > 8 files changed, 435 insertions(+), 348 deletions(-) > rename Documentation/devicetree/bindings/{arm/topology.txt => cpu/cpu-topology.txt} (66%) > > -- > 2.7.4 > Seems to test fine on QDF2400. Tested-by: Jeffrey Hugo <jhugo@codeaurora.org> I did see that git am complained about patch #2 - patch:103: space before tab in indent. }; patch:114: space before tab in indent. }; warning: 2 lines add whitespace errors.
Hi, On Thu, Nov 29, 2018 at 03:28:16PM -0800, Atish Patra wrote: > The cpu-map DT entry in ARM64 can describe the CPU topology in > much better way compared to other existing approaches. RISC-V can > easily adopt this binding to represent it's 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 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. > > The patches have been tested for RISC-V and compile tested for > ARM64 & x86. The cpu-map bindings are used for arch/arm too, and so is arch_topology.c. In fact, it was introduced to allow code-sharing between arm and arm64. Applying patch three breaks arm. Moving the DT parsing to arch_topology.c we have to unify all three architectures. Be aware that arm and arm64 have some differences in how they detect cpu capacities. I think we might have to look at the split of code between arch/* and arch_topology.c again :-/ Morten
On Fri, Dec 07, 2018 at 01:45:21PM +0000, Morten Rasmussen wrote: > Hi, > > On Thu, Nov 29, 2018 at 03:28:16PM -0800, Atish Patra wrote: > > The cpu-map DT entry in ARM64 can describe the CPU topology in > > much better way compared to other existing approaches. RISC-V can > > easily adopt this binding to represent it's 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 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. > > > > The patches have been tested for RISC-V and compile tested for > > ARM64 & x86. > > The cpu-map bindings are used for arch/arm too, and so is > arch_topology.c. In fact, it was introduced to allow code-sharing > between arm and arm64. Applying patch three breaks arm. > Ah right. Though I remember the whole point of moving these to arch_topology was to share between ARM and ARM64, I completely forgot to check the impact of this for ARM platforms. > Moving the DT parsing to arch_topology.c we have to unify all three > architectures. Be aware that arm and arm64 have some differences in how > they detect cpu capacities. I think we might have to look at the split > of code between arch/* and arch_topology.c again :-/ > Thanks for pointing this out. I completely agree and apologies for forgetting about arm32. Regards, Sudeep
On 12/7/18 5:45 AM, Morten Rasmussen wrote: > Hi, > > On Thu, Nov 29, 2018 at 03:28:16PM -0800, Atish Patra wrote: >> The cpu-map DT entry in ARM64 can describe the CPU topology in >> much better way compared to other existing approaches. RISC-V can >> easily adopt this binding to represent it's 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 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. >> >> The patches have been tested for RISC-V and compile tested for >> ARM64 & x86. > > The cpu-map bindings are used for arch/arm too, and so is > arch_topology.c. In fact, it was introduced to allow code-sharing > between arm and arm64. Applying patch three breaks arm. > > Moving the DT parsing to arch_topology.c we have to unify all three > architectures. Be aware that arm and arm64 have some differences in how > they detect cpu capacities. I think we might have to look at the split > of code between arch/* and arch_topology.c again :-/ > > Morten > Thank you for bringing this up. I will send a new version and make sure that it works on arm32 as well. Regards, Atish
On 12/5/18 9:53 AM, Jeffrey Hugo wrote: > On 11/29/2018 4:28 PM, Atish Patra wrote: >> The cpu-map DT entry in ARM64 can describe the CPU topology in >> much better way compared to other existing approaches. RISC-V can >> easily adopt this binding to represent it's 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 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. >> >> The patches have been tested for RISC-V and compile tested for >> ARM64 & 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/riscv-qemu/tree/cpu_topo >> >> Apologies for the previous patch series with incorrect title and >> was sent only to kernel mailing list due to a bug in my config. >> Please ignore that. >> >> Atish Patra (3): >> dt-binding: cpu-topology: Move cpu-map to a common binding. >> cpu-topology: Move cpu topology code to common code. >> RISC-V: Parse cpu topology during boot. >> >> Sudeep Holla (1): >> Documentation: DT: arm: add support for sockets defining package >> boundaries >> >> .../{arm/topology.txt => cpu/cpu-topology.txt} | 133 +++++++-- >> arch/arm64/include/asm/topology.h | 22 -- >> arch/arm64/kernel/topology.c | 303 +-------------------- >> arch/riscv/Kconfig | 1 + >> arch/riscv/kernel/smpboot.c | 3 + >> drivers/base/arch_topology.c | 294 ++++++++++++++++++++ >> include/linux/arch_topology.h | 26 ++ >> include/linux/topology.h | 1 + >> 8 files changed, 435 insertions(+), 348 deletions(-) >> rename Documentation/devicetree/bindings/{arm/topology.txt => cpu/cpu-topology.txt} (66%) >> >> -- >> 2.7.4 >> > > Seems to test fine on QDF2400. > > Tested-by: Jeffrey Hugo <jhugo@codeaurora.org> > Thanks for verifying the patches. > I did see that git am complained about patch #2 - > > patch:103: space before tab in indent. > }; > patch:114: space before tab in indent. > }; > warning: 2 lines add whitespace errors. > > Thanks for pointing it out. For some reason, cherry-pick did not complain about these. I will fix them. Regards, Atish
The cpu-map DT entry in ARM64 can describe the CPU topology in much better way compared to other existing approaches. RISC-V can easily adopt this binding to represent it's 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 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. The patches have been tested for RISC-V and compile tested for ARM64 & 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/riscv-qemu/tree/cpu_topo Apologies for the previous patch series with incorrect title and was sent only to kernel mailing list due to a bug in my config. Please ignore that. Atish Patra (3): dt-binding: cpu-topology: Move cpu-map to a common binding. cpu-topology: Move cpu topology code to common code. RISC-V: Parse cpu topology during boot. Sudeep Holla (1): Documentation: DT: arm: add support for sockets defining package boundaries .../{arm/topology.txt => cpu/cpu-topology.txt} | 133 +++++++-- arch/arm64/include/asm/topology.h | 22 -- arch/arm64/kernel/topology.c | 303 +-------------------- arch/riscv/Kconfig | 1 + arch/riscv/kernel/smpboot.c | 3 + drivers/base/arch_topology.c | 294 ++++++++++++++++++++ include/linux/arch_topology.h | 26 ++ include/linux/topology.h | 1 + 8 files changed, 435 insertions(+), 348 deletions(-) rename Documentation/devicetree/bindings/{arm/topology.txt => cpu/cpu-topology.txt} (66%) -- 2.7.4