• Mike Travis's avatar
    x86: Limit the number of processor bootup messages · 2eaad1fd
    Mike Travis authored
    When there are a large number of processors in a system, there
    is an excessive amount of messages sent to the system console.
    It's estimated that with 4096 processors in a system, and the
    console baudrate set to 56K, the startup messages will take
    about 84 minutes to clear the serial port.
    
    This set of patches limits the number of repetitious messages
    which contain no additional information.  Much of this information
    is obtainable from the /proc and /sysfs.   Some of the messages
    are also sent to the kernel log buffer as KERN_DEBUG messages so
    dmesg can be used to examine more closely any details specific to
    a problem.
    
    The new cpu bootup sequence for system_state == SYSTEM_BOOTING:
    
    Booting Node   0, Processors  #1 #2 #3 #4 #5 #6 #7 Ok.
    Booting Node   1, Processors  #8 #9 #10 #11 #12 #13 #14 #15 Ok.
    ...
    Booting Node   3, Processors  #56 #57 #58 #59 #60 #61 #62 #63 Ok.
    Brought up 64 CPUs
    
    After the system is running, a single line boot message is displayed
    when CPU's are hotplugged on:
    
        Booting Node %d Processor %d APIC 0x%x
    
    Status of the following lines:
    
        CPU: Physical Processor ID:		printed once (for boot cpu)
        CPU: Processor Core ID:		printed once (for boot cpu)
        CPU: Hyper-Threading is disabled	printed once (for boot cpu)
        CPU: Thermal monitoring enabled	printed once (for boot cpu)
        CPU %d/0x%x -> Node %d:		removed
        CPU %d is now offline:		only if system_state == RUNNING
        Initializing CPU#%d:		KERN_DEBUG
    Signed-off-by: default avatarMike Travis <travis@sgi.com>
    LKML-Reference: <4B219E28.8080601@sgi.com>
    Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
    2eaad1fd
smpboot.c 33 KB