• Jack Steiner's avatar
    [IA64] Hole in IA64 TLB flushing from system threads · cfbb1426
    Jack Steiner authored
    I originally thought this was an bug only in the SN code, but I think I
    also see a hole in the generic IA64 tlb code. (Separate patch was sent
    for the SN problem).
    
    It looks like there is a bug in the TLB flushing code. During context switch,
    kernel threads (kswapd, for example) inherit the mm of the task that was
    previously running on the cpu. Normally, this is ok because the previous context
    is still loaded into the RR registers. However, if the owner of the mm
    migrates to another cpu, changes it's context number, and references a
    page before kswapd issues a tlb_purge for that same page, the purge will be
    done with a stale context number (& RR registers).
    Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
    cfbb1426
tlb.c 4.65 KB