From: "Joel Fernandes (Google)" <[email protected]> Moving page-tables at the PMD-level on x86 is known to be safe. Enable this option so that we can do fast mremap when possible.
Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Joel Fernandes (Google) <[email protected]> Suggested-by: Kirill A. Shutemov <[email protected]> Acked-by: Kirill A. Shutemov <[email protected]> Cc: Julia Lawall <[email protected]> Cc: Michal Hocko <[email protected]> Cc: William Kucharski <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> (cherry picked from commit 9f132f7e145506efc0744426cb338b18a54afc3b) Signed-off-by: Kirill Tkhai <[email protected]> Patchset description: Patch "mm: speed up mremap by 20x on large regions" introduces optimization: when a moved region has source and destination addresses and size equal to multiple of PMD_SIZE; PTEs are not really copyed. Instead of this, new PMD pointer is changed to point to old PTEs, while old PMD is cleared. This may be useful, when CRIU remaps large memory areas on restore (but really, alignment to PMD_SIZE is not very often, though possible). (cherry-picked from ms 9f132f7e145506efc0744426cb338b18a54afc3b) Signed-off-by: Andrey Zhadchenko <[email protected]> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index d90d31e..fb22076 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -186,6 +186,7 @@ config X86 select HAVE_MEMBLOCK_NODE_MAP select HAVE_MIXED_BREAKPOINTS_REGS select HAVE_MOD_ARCH_SPECIFIC + select HAVE_MOVE_PMD select HAVE_NMI select HAVE_OPROFILE select HAVE_OPTPROBES -- 1.8.3.1 _______________________________________________ Devel mailing list [email protected] https://lists.openvz.org/mailman/listinfo/devel
