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-rw-r--r--Documentation/features/sched/membarrier-sync-core/arch-support.txt54
-rw-r--r--Documentation/features/sched/numa-balancing/arch-support.txt31
2 files changed, 85 insertions, 0 deletions
diff --git a/Documentation/features/sched/membarrier-sync-core/arch-support.txt b/Documentation/features/sched/membarrier-sync-core/arch-support.txt
new file mode 100644
index 000000000..336d728b8
--- /dev/null
+++ b/Documentation/features/sched/membarrier-sync-core/arch-support.txt
@@ -0,0 +1,54 @@
+#
+# Feature name: membarrier-sync-core
+# Kconfig: ARCH_HAS_MEMBARRIER_SYNC_CORE
+# description: arch supports core serializing membarrier
+#
+# Architecture requirements
+#
+# * arm/arm64/powerpc
+#
+# Rely on implicit context synchronization as a result of exception return
+# when returning from IPI handler, and when returning to user-space.
+#
+# * x86
+#
+# x86-32 uses IRET as return from interrupt, which takes care of the IPI.
+# However, it uses both IRET and SYSEXIT to go back to user-space. The IRET
+# instruction is core serializing, but not SYSEXIT.
+#
+# x86-64 uses IRET as return from interrupt, which takes care of the IPI.
+# However, it can return to user-space through either SYSRETL (compat code),
+# SYSRETQ, or IRET.
+#
+# Given that neither SYSRET{L,Q}, nor SYSEXIT, are core serializing, we rely
+# instead on write_cr3() performed by switch_mm() to provide core serialization
+# after changing the current mm, and deal with the special case of kthread ->
+# uthread (temporarily keeping current mm into active_mm) by issuing a
+# sync_core_before_usermode() in that specific case.
+#
+ -----------------------
+ | arch |status|
+ -----------------------
+ | alpha: | TODO |
+ | arc: | TODO |
+ | arm: | ok |
+ | arm64: | ok |
+ | csky: | TODO |
+ | hexagon: | TODO |
+ | ia64: | TODO |
+ | loong: | TODO |
+ | m68k: | TODO |
+ | microblaze: | TODO |
+ | mips: | TODO |
+ | nios2: | TODO |
+ | openrisc: | TODO |
+ | parisc: | TODO |
+ | powerpc: | ok |
+ | riscv: | TODO |
+ | s390: | TODO |
+ | sh: | TODO |
+ | sparc: | TODO |
+ | um: | TODO |
+ | x86: | ok |
+ | xtensa: | TODO |
+ -----------------------
diff --git a/Documentation/features/sched/numa-balancing/arch-support.txt b/Documentation/features/sched/numa-balancing/arch-support.txt
new file mode 100644
index 000000000..76d012118
--- /dev/null
+++ b/Documentation/features/sched/numa-balancing/arch-support.txt
@@ -0,0 +1,31 @@
+#
+# Feature name: numa-balancing
+# Kconfig: ARCH_SUPPORTS_NUMA_BALANCING
+# description: arch supports NUMA balancing
+#
+ -----------------------
+ | arch |status|
+ -----------------------
+ | alpha: | TODO |
+ | arc: | .. |
+ | arm: | .. |
+ | arm64: | ok |
+ | csky: | .. |
+ | hexagon: | .. |
+ | ia64: | TODO |
+ | loong: | ok |
+ | m68k: | .. |
+ | microblaze: | .. |
+ | mips: | TODO |
+ | nios2: | .. |
+ | openrisc: | .. |
+ | parisc: | .. |
+ | powerpc: | ok |
+ | riscv: | ok |
+ | s390: | ok |
+ | sh: | .. |
+ | sparc: | TODO |
+ | um: | .. |
+ | x86: | ok |
+ | xtensa: | .. |
+ -----------------------