* Ingo Molnar [off-list ref] wrote:

* Stephen Rothwell [off-list ref] wrote:

quoted

Hi Ingo,

Thanks for this.  The concept is certainly good.

On Thu, 14 May 2015 21:59:25 +0200 Ingo Molnar [off-list ref] wrote:

quoted

The patch that adds a new architecture to all these files would give 
us a good overview about how complete an initial port is.

If you want to test how hard that is (and what sort of patch it
produces), the h8300 architecture was added to linux-next recently.

I tried this out, this is the resulting feature support matrix for the 
new h8300 architecture:

#
# Kernel feature support matrix of architecture 'h8300':
#
           arch-tick-broadcast:     |       h8300: | TODO |
                       BPF-JIT:     |       h8300: | TODO |

Perhaps the more verbose table is more useful:

#
# Kernel feature support matrix of architecture 'h8300':
#
   arch-tick-broadcast:  | TODO |                            ARCH_HAS_TICK_BROADCAST #  arch provides tick_broadcast()
               BPF-JIT:  | TODO |                                       HAVE_BPF_JIT #  arch supports BPF JIT optimizations
           clockevents:  |  ok  |                                GENERIC_CLOCKEVENTS #  arch support generic clock events
         cmpxchg-local:  | TODO |                                 HAVE_CMPXCHG_LOCAL #  arch supports the this_cpu_cmpxchg() API
      context-tracking:  | TODO |                              HAVE_CONTEXT_TRACKING #  arch supports context tracking for NO_HZ_FULL
         dma-api-debug:  | TODO |                                 HAVE_DMA_API_DEBUG #  arch supports DMA debug facilities
        dma-contiguous:  | TODO |                                HAVE_DMA_CONTIGUOUS #  arch supports the DMA CMA (continuous memory allocator)
         dma_map_attrs:  |  ok  |                                     HAVE_DMA_ATTRS #  arch provides dma_*map*_attrs() APIs
              ELF-ASLR:  | TODO |                             ARCH_HAS_ELF_RANDOMIZE #  arch randomizes the stack, heap and binary images of ELF binaries
      gcov-profile-all:  | TODO |                          ARCH_HAS_GCOV_PROFILE_ALL #  arch supports whole-kernel GCOV code coverage profiling
   generic-idle-thread:  | TODO |                            GENERIC_SMP_IDLE_THREAD #  arch makes use of the generic SMP idle thread facility
             huge-vmap:  | TODO |                                HAVE_ARCH_HUGE_VMAP #  arch supports the ioremap_pud_enabled() and ioremap_pmd_enabled() VM APIs
          ioremap_prot:  | TODO |                                  HAVE_IOREMAP_PROT #  arch has ioremap_prot()
         irq-time-acct:  | TODO |                           HAVE_IRQ_TIME_ACCOUNTING #  arch supports precise IRQ time accounting
           jump-labels:  | TODO |                               HAVE_ARCH_JUMP_LABEL #  arch supports live patched high efficiency branches
                 KASAN:  | TODO |                                    HAVE_ARCH_KASAN #  arch supports the KASAN runtime memory checker
                  kgdb:  | TODO |                                     HAVE_ARCH_KGDB #  arch supports the kGDB kernel debugger
               kprobes:  | TODO |                                       HAVE_KPROBES #  arch supports live patched kernel probe
         kprobes-event:  | TODO |                     HAVE_REGS_AND_STACK_ACCESS_API #  arch supports kprobes with perf events
     kprobes-on-ftrace:  | TODO |                             HAVE_KPROBES_ON_FTRACE #  arch supports combined kprobes and ftrace live patching
            kretprobes:  | TODO |                                    HAVE_KRETPROBES #  arch supports kernel function-return probes
               lockdep:  | TODO |                                    LOCKDEP_SUPPORT #  arch supports the runtime locking correctness debug facility
    modern-timekeeping:  |  ok  |                           !ARCH_USES_GETTIMEOFFSET #  arch does not use arch_gettimeoffset() anymore
        numa-balancing:  |  ..  |      ARCH_SUPPORTS_NUMA_BALANCING && 64BIT && NUMA #  arch supports NUMA balancing
         numa-memblock:  |  ..  |                             HAVE_MEMBLOCK_NODE_MAP #  arch supports NUMA aware memblocks
             optprobes:  | TODO |                                     HAVE_OPTPROBES #  arch supports live patched optprobes
             perf-regs:  | TODO |                                     HAVE_PERF_REGS #  arch supports perf events register access
        perf-stackdump:  | TODO |                          HAVE_PERF_USER_STACK_DUMP #  arch supports perf events stack dumps
           PG_uncached:  | TODO |                              ARCH_USES_PG_UNCACHED #  arch supports the PG_uncached page flag
  pmdp_splitting_flush:  | TODO |           #define __HAVE_ARCH_PMDP_SPLITTING_FLUSH #  arch supports the pmdp_splitting_flush() VM API
           pte_special:  | TODO |                    #define __HAVE_ARCH_PTE_SPECIAL #  arch supports the pte_special()/pte_mkspecial() VM APIs
        queued-rwlocks:  | TODO |                            ARCH_USE_QUEUED_RWLOCKS #  arch supports queued rwlocks
      queued-spinlocks:  | TODO |                          ARCH_USE_QUEUED_SPINLOCKS #  arch supports queued spinlocks
       rwsem-optimized:  |  ok  |                              Optimized asm/rwsem.h #  arch provides optimized rwsem APIs
        seccomp-filter:  | TODO |                           HAVE_ARCH_SECCOMP_FILTER #  arch supports seccomp filters
              sg-chain:  | TODO |                                  ARCH_HAS_SG_CHAIN #  arch supports chained scatter-gather lists
        stackprotector:  | TODO |                             HAVE_CC_STACKPROTECTOR #  arch supports compiler driven stack overflow protection
           strncasecmp:  | TODO |                            __HAVE_ARCH_STRNCASECMP #  arch provides an optimized strncasecmp() function
                   THP:  |  ..  |            HAVE_ARCH_TRANSPARENT_HUGEPAGE && 64BIT #  arch supports transparent hugepages
             tracehook:  | TODO |                                HAVE_ARCH_TRACEHOOK #  arch supports tracehook (ptrace) register handling APIs
               uprobes:  | TODO |                              ARCH_SUPPORTS_UPROBES #  arch supports live patched user probes
     user-ret-profiler:  | TODO |                          HAVE_USER_RETURN_NOTIFIER #  arch supports user-space return from system call profiler
          virt-cpuacct:  | TODO |                  HAVE_VIRT_CPU_ACCOUNTING || 64BIT #  arch supports precise virtual CPU time accounting

Thanks,

	Ingo