From: "Kirill A. Shutemov" <[email protected]>
Clearing a 2MB huge page will typically blow away several levels of CPU caches. To avoid this only cache clear the 4K area around the fault address and use a cache avoiding clears for the rest of the 2MB area. It would be nice to test the patchset with more workloads. Especially if you see performance regression with THP. Any feedback is appreciated. Andi Kleen (6): THP: Use real address for NUMA policy mm: make clear_huge_page tolerate non aligned address THP: Pass real, not rounded, address to clear_huge_page x86: Add clear_page_nocache mm: make clear_huge_page cache clear only around the fault address x86: switch the 64bit uncached page clear to SSE/AVX v2 arch/x86/include/asm/page.h | 2 + arch/x86/include/asm/string_32.h | 5 ++ arch/x86/include/asm/string_64.h | 5 ++ arch/x86/lib/Makefile | 1 + arch/x86/lib/clear_page_nocache_32.S | 30 +++++++++++ arch/x86/lib/clear_page_nocache_64.S | 92 ++++++++++++++++++++++++++++++++++ arch/x86/mm/fault.c | 7 +++ mm/huge_memory.c | 17 +++--- mm/memory.c | 29 ++++++++++- 9 files changed, 178 insertions(+), 10 deletions(-) create mode 100644 arch/x86/lib/clear_page_nocache_32.S create mode 100644 arch/x86/lib/clear_page_nocache_64.S -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
