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SubjectRe: [PATCH v2 0/8] Improve performance of VM translation on x86_64
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On Thu, Oct 11, 2012 at 4:49 PM, Alexander Duyck
<alexander.h.duyck@intel.com> wrote:
> 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.
>

Could you also add a blurb in the Documentation/< appropriate file
for device driver writes> mentioning the usage of __pa_symbol is
preferred?

> ---
>
> 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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