• Cliff Wickman's avatar
    x86, UV: Make kdump avoid stack dumps · 5edd19af
    Cliff Wickman authored
    UV NMI callback's should not write stack dumps when a kdump is to be written.
    
    When invoking the crash kernel to write a dump, kdump_nmi_shootdown_cpus()
    uses NMI's to get all the cpu's to save their register context and halt.
    
    But the NMI interrupt handler runs a callback list.  This patch sets a flag
    to prevent any of those callbacks from interfering with the halt of the cpu.
    
    For UV, which currently has the only callback to which this is relevant, the
    uv_handle_nmi() callback should not do dumping of stacks.
    
    The 'in_crash_kexec' flag is defined as an extern in kdebug.h firstly
    because x2apic_uv_x.c includes it.  Secondly because some future callback
    might need the flag to know that it should not enter the debugger.
    (Such a scenario was in fact present in the 2.6.32 kernel, SuSE distribution,
     where a call to kdb needed to be avoided.)
    Signed-off-by: default avatarCliff Wickman <cpw@sgi.com>
    LKML-Reference: <E1ObLvt-0005UZ-Va@eag09.americas.sgi.com>
    Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
    5edd19af
x2apic_uv_x.c 19.3 KB