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Diffstat (limited to 'arch/x86/Kconfig.debug')
| -rw-r--r-- | arch/x86/Kconfig.debug | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index e46c2147397f..b322f124ee3c 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -129,6 +129,25 @@ config DOUBLEFAULT option saves about 4k and might cause you much additional grey hair. +config DEBUG_TLBFLUSH + bool "Set upper limit of TLB entries to flush one-by-one" + depends on DEBUG_KERNEL && (X86_64 || X86_INVLPG) + ---help--- + + 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". + config IOMMU_DEBUG bool "Enable IOMMU debugging" depends on GART_IOMMU && DEBUG_KERNEL |