Srikar Dronamraju <sri...@linux.vnet.ibm.com> writes:
> Currently there are four powerpc specific sched topologies. These are
> all statically defined. However not all these topologies are used by
> all powerpc systems.
>
> To avoid unnecessary degenerations by the scheduler , masks and flags
> are compared. However if the sched topologies are build dynamically then
> the code is simpler and there are greater chances of avoiding
> degenerations.
>
> Even x86 builds its sched topologies dynamically and new changes are
> very similar to the way x86 is building its topologies.
>
> System Configuration
> type=Shared mode=Uncapped smt=8 lcpu=128 mem=1063126592 kB cpus=96 ent=40.00
>
> $ lscpu
> Architecture: ppc64le
> Byte Order: Little Endian
> CPU(s): 1024
> On-line CPU(s) list: 0-1023
> Model name: POWER10 (architected), altivec supported
> Model: 2.0 (pvr 0080 0200)
> Thread(s) per core: 8
> Core(s) per socket: 32
> Socket(s): 4
> Hypervisor vendor: pHyp
> Virtualization type: para
> L1d cache: 8 MiB (256 instances)
> L1i cache: 12 MiB (256 instances)
> NUMA node(s): 4
>
> From dmesg of v6.5
> [ 0.174444] smp: Bringing up secondary CPUs ...
> [ 3.918535] smp: Brought up 4 nodes, 1024 CPUs
> [ 38.001402] sysrq: Changing Loglevel
> [ 38.001446] sysrq: Loglevel set to 9
>
> From dmesg of v6.5 + patch
> [ 0.174462] smp: Bringing up secondary CPUs ...
> [ 3.421462] smp: Brought up 4 nodes, 1024 CPUs
> [ 35.417917] sysrq: Changing Loglevel
> [ 35.417959] sysrq: Loglevel set to 9
>
> 5 runs of ppc64_cpu --smt=1 (time measured: lesser is better)
> Kernel N Min Max Median Avg Stddev %Change
> v6.5 5 518.08 574.27 528.61 535.388 22.341542
> +patch 5 481.73 495.47 484.21 486.402 5.7997 -9.14963
>
> 5 runs of ppc64_cpu --smt=8 (time measured: lesser is better)
> Kernel N Min Max Median Avg Stddev %Change
> v6.5 5 1094.12 1117.1 1108.97 1106.3 8.606361
> +patch 5 1067.5 1090.03 1073.89 1076.574 9.4189347 -2.68697
>
> Signed-off-by: Srikar Dronamraju <sri...@linux.vnet.ibm.com>
> ---
> arch/powerpc/kernel/smp.c | 78 ++++++++++++++-------------------------
> 1 file changed, 28 insertions(+), 50 deletions(-)
>
> diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
> index 48b8161179a8..c16443a04c26 100644
> --- a/arch/powerpc/kernel/smp.c
> +++ b/arch/powerpc/kernel/smp.c
> @@ -92,15 +92,6 @@ EXPORT_PER_CPU_SYMBOL(cpu_l2_cache_map);
> EXPORT_PER_CPU_SYMBOL(cpu_core_map);
> EXPORT_SYMBOL_GPL(has_big_cores);
>
> -enum {
> -#ifdef CONFIG_SCHED_SMT
> - smt_idx,
> -#endif
> - cache_idx,
> - mc_idx,
> - die_idx,
> -};
> -
> #define MAX_THREAD_LIST_SIZE 8
> #define THREAD_GROUP_SHARE_L1 1
> #define THREAD_GROUP_SHARE_L2_L3 2
> @@ -1048,16 +1039,6 @@ static const struct cpumask *cpu_mc_mask(int cpu)
> return cpu_coregroup_mask(cpu);
> }
>
> -static struct sched_domain_topology_level powerpc_topology[] = {
> -#ifdef CONFIG_SCHED_SMT
> - { cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) },
> -#endif
> - { shared_cache_mask, powerpc_shared_cache_flags, SD_INIT_NAME(CACHE) },
> - { cpu_mc_mask, powerpc_shared_proc_flags, SD_INIT_NAME(MC) },
> - { cpu_cpu_mask, powerpc_shared_proc_flags, SD_INIT_NAME(DIE) },
> - { NULL, },
> -};
This doesn't apply on my next or upstream.
It looks like it depends on your other 6-patch series. Please append
this patch to that series.
cheers
