Messages in this thread | | | Date | Fri, 12 Oct 2012 10:12:53 -0400 | Subject | Re: [PATCH v2 0/8] Improve performance of VM translation on x86_64 | From | Konrad Rzeszutek Wilk <> |
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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(-) > > -- > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
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