[PATCH v2 0/8] Improve performance of VM translation on x86_64

From: Alexander Duyck
Date: Thu Oct 11 2012 - 16:49:27 EST


This patch series is meant to address several issues I encountered with VM
translations on x86_64. In my testing I found that swiotlb was incurring up
to a 5% processing overhead due to calls to __phys_addr. To address that I
have updated swiotlb to use physical addresses instead of virtual addresses
to reduce the need to call __phys_addr. However those patches didn't address
the other callers. With these patches applied I am able to achieve an
additional 1% to 2% performance gain on top of the changes to swiotlb.

The first 2 patches are the performance optimizations that result in the 1% to
2% increase in overall performance. The remaining patches are various
cleanups for a number of spots where __pa or virt_to_phys was being called
and was not needed or __pa_symbol could have been used.

---

Alexander Duyck (8):
x86/lguest: Use __pa_symbol instead of __pa on C visible symbols
x86/acpi: Use __pa_symbol instead of __pa on C visible symbols
x86/xen: Use __pa_symbol instead of __pa on C visible symbols
x86/ftrace: Use __pa_symbol instead of __pa on C visible symbols
x86: Use __pa_symbol instead of __pa on C visible symbols
x86: Drop 4 unnecessary calls to __pa_symbol
x86: Make it so that __pa_symbol can only process kernel symbols on x86_64
x86: Improve __phys_addr performance by making use of carry flags and inlining


arch/x86/include/asm/page.h | 3 ++-
arch/x86/include/asm/page_32.h | 1 +
arch/x86/include/asm/page_64_types.h | 20 +++++++++++++++++--
arch/x86/kernel/acpi/sleep.c | 2 +-
arch/x86/kernel/cpu/intel.c | 2 +-
arch/x86/kernel/ftrace.c | 4 ++--
arch/x86/kernel/head32.c | 4 ++--
arch/x86/kernel/head64.c | 4 ++--
arch/x86/kernel/setup.c | 16 ++++++++--------
arch/x86/kernel/x8664_ksyms_64.c | 3 +++
arch/x86/lguest/boot.c | 3 ++-
arch/x86/mm/pageattr.c | 8 ++++----
arch/x86/mm/physaddr.c | 35 ++++++++++++++++++++++++++++------
arch/x86/platform/efi/efi.c | 4 ++--
arch/x86/realmode/init.c | 8 ++++----
arch/x86/xen/mmu.c | 19 ++++++++++--------
16 files changed, 91 insertions(+), 45 deletions(-)

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