• Fenghua Yu's avatar
    x86/resctrl: Enable user to view thread or core throttling mode · 29b6bd41
    Fenghua Yu authored
    Early Intel hardware implementations of Memory Bandwidth Allocation (MBA)
    could only control bandwidth at the processor core level. This meant that
    when two processes with different bandwidth allocations ran simultaneously
    on the same core the hardware had to resolve this difference. It did so by
    applying the higher throttling value (lower bandwidth) to both processes.
    
    Newer implementations can apply different throttling values to each
    thread on a core.
    
    Introduce a new resctrl file, "thread_throttle_mode", on Intel systems
    that shows to the user how throttling values are allocated, per-core or
    per-thread.
    
    On systems that support per-core throttling, the file will display "max".
    On newer systems that support per-thread throttling, the file will display
    "per-thread".
    
    AMD confirmed in [1] that AMD bandwidth allocation is already at thread
    level but that the AMD implementation does not use a memory delay
    throttle mode. So to avoid confusion t...
    29b6bd41
resctrl_ui.rst 42.7 KB