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author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-02-15 09:28:47 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-02-15 09:28:47 -0800 |
commit | 1388c80438e69fc01d83fbe98da3cac24c3c8731 (patch) | |
tree | 5014b653431a4b4fafb1e952dddf0ffcce9387a2 /Documentation | |
parent | e9e3b3002fc3c9ef665628bd85a8c1b5a3424f23 (diff) | |
parent | 43d1b29b27c76e7454cd6c85bec4d0e9cbb039f3 (diff) |
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
"Misc fixes:
- fix rq->lock lockdep annotation bug
- fix/improve update_curr_rt() and update_curr_dl() accounting
- update documentation
- remove unused macro"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/cpufreq: Remove unused SUGOV_KTHREAD_PRIORITY macro
sched/core: Fix DEBUG_SPINLOCK annotation for rq->lock
sched/rt: Make update_curr_rt() more accurate
sched/deadline: Make update_curr_dl() more accurate
membarrier-sync-core: Document architecture support
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/features/sched/membarrier-sync-core/arch-support.txt | 62 |
1 files changed, 62 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 000000000000..2c815a7f1ba7 --- /dev/null +++ b/Documentation/features/sched/membarrier-sync-core/arch-support.txt @@ -0,0 +1,62 @@ +# +# Feature name: membarrier-sync-core +# Kconfig: ARCH_HAS_MEMBARRIER_SYNC_CORE +# description: arch supports core serializing membarrier +# +# Architecture requirements +# +# * arm64 +# +# Rely on eret context synchronization 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: | TODO | + | arm64: | ok | + | blackfin: | TODO | + | c6x: | TODO | + | cris: | TODO | + | frv: | TODO | + | h8300: | TODO | + | hexagon: | TODO | + | ia64: | TODO | + | m32r: | TODO | + | m68k: | TODO | + | metag: | TODO | + | microblaze: | TODO | + | mips: | TODO | + | mn10300: | TODO | + | nios2: | TODO | + | openrisc: | TODO | + | parisc: | TODO | + | powerpc: | TODO | + | s390: | TODO | + | score: | TODO | + | sh: | TODO | + | sparc: | TODO | + | tile: | TODO | + | um: | TODO | + | unicore32: | TODO | + | x86: | ok | + | xtensa: | TODO | + ----------------------- |