Set upper limit of TLB entries to flush one-by-one
configname: CONFIG_DEBUG_TLBFLUSH
Linux Kernel Configuration
└─>Kernel hacking
└─>$(SRCARCH) Debugging
└─>Set upper limit of TLB entries to flush one-by-one
In linux kernel since version 3.1 (release Date: 2011-10-24)
X86-only for now.
This option allows the user to tune the amount of TLB entries the
kernel flushes one-by-one instead of doing a full TLB flush. In
certain situations, the former is cheaper. This is controlled by the
tlb_flushall_shift knob under /sys/kernel/debug/x86. If you set it
to -1, the code flushes the whole TLB unconditionally. Otherwise,
for positive values of it, the kernel will use single TLB entry
invalidating instructions according to the following formula:
flush_entries <= active_tlb_entries / 2^tlb_flushall_shift
If in doubt, say "N".
This option allows the user to tune the amount of TLB entries the
kernel flushes one-by-one instead of doing a full TLB flush. In
certain situations, the former is cheaper. This is controlled by the
tlb_flushall_shift knob under /sys/kernel/debug/x86. If you set it
to -1, the code flushes the whole TLB unconditionally. Otherwise,
for positive values of it, the kernel will use single TLB entry
invalidating instructions according to the following formula:
flush_entries <= active_tlb_entries / 2^tlb_flushall_shift
If in doubt, say "N".