Commits
Thomas Gleixner committed 1c4b406ee89
x86/mm/cpa: Optimize same protection check When the existing mapping is correct and the new requested page protections are the same as the existing ones, then further checks can be omitted and the large page can be preserved. The slow path 4k wise check will not come up with a different result. Before: 1G pages checked: 2 1G pages sameprot: 0 1G pages preserved: 0 2M pages checked: 540 2M pages sameprot: 466 2M pages preserved: 47 4K pages checked: 800709 4K pages set-checked: 7668 After: 1G pages checked: 2 1G pages sameprot: 0 1G pages preserved: 0 2M pages checked: 538 2M pages sameprot: 466 2M pages preserved: 47 4K pages checked: 560642 4K pages set-checked: 7668 Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Bin Yang <bin.yang@intel.com> Cc: Mark Gross <mark.gross@intel.com> Link: https://lkml.kernel.org/r/20180917143546.424477581@linutronix.de