Messages in this thread | | | Subject | Re: [PATCH 3/3, v2] x86/xor: make virtualization friendly | From | "H. Peter Anvin" <> | Date | Fri, 02 Nov 2012 10:30:08 -0700 |
| |
Aren't we actually talking just about PV here?
If so the test is wrong.
Jan Beulich <JBeulich@suse.com> wrote:
>In virtualized environments, the CR0.TS management needed here can be a >lot slower than anticipated by the original authors of this code, which >particularly means that in such cases forcing the use of SSE- (or MMX-) >based implementations is not desirable - actual measurements should >always be done in that case. > >For consistency, pull into the shared (32- and 64-bit) header not only >the inclusion of the generic code, but also that of the AVX variants. > >Signed-off-by: Jan Beulich <jbeulich@suse.com> >Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > >--- > arch/x86/include/asm/xor.h | 8 +++++++- > arch/x86/include/asm/xor_32.h | 22 ++++++++++------------ > arch/x86/include/asm/xor_64.h | 10 ++++++---- > 3 files changed, 23 insertions(+), 17 deletions(-) > >--- 3.7-rc3-x86-xor.orig/arch/x86/include/asm/xor.h >+++ 3.7-rc3-x86-xor/arch/x86/include/asm/xor.h >@@ -487,6 +487,12 @@ static struct xor_block_template xor_blo > > #undef XOR_CONSTANT_CONSTRAINT > >+/* Also try the AVX routines */ >+#include <asm/xor_avx.h> >+ >+/* Also try the generic routines. */ >+#include <asm-generic/xor.h> >+ > #ifdef CONFIG_X86_32 > # include <asm/xor_32.h> > #else >@@ -494,6 +500,6 @@ static struct xor_block_template xor_blo > #endif > > #define XOR_SELECT_TEMPLATE(FASTEST) \ >- AVX_SELECT(FASTEST) >+ (cpu_has_hypervisor ? (FASTEST) : AVX_SELECT(FASTEST)) > > #endif /* _ASM_X86_XOR_H */ >--- 3.7-rc3-x86-xor.orig/arch/x86/include/asm/xor_32.h >+++ 3.7-rc3-x86-xor/arch/x86/include/asm/xor_32.h >@@ -537,12 +537,6 @@ static struct xor_block_template xor_blo > .do_5 = xor_sse_5, > }; > >-/* Also try the AVX routines */ >-#include <asm/xor_avx.h> >- >-/* Also try the generic routines. */ >-#include <asm-generic/xor.h> >- >/* We force the use of the SSE xor block because it can write around >L2. > We may also be able to load into the L1 only depending on how the cpu > deals with a load to a line that is being prefetched. */ >@@ -553,15 +547,19 @@ do { \ > if (cpu_has_xmm) { \ > xor_speed(&xor_block_pIII_sse); \ > xor_speed(&xor_block_sse_pf64); \ >- } else if (cpu_has_mmx) { \ >+ if (!cpu_has_hypervisor) \ >+ break; \ >+ } \ >+ if (cpu_has_mmx) { \ > xor_speed(&xor_block_pII_mmx); \ > xor_speed(&xor_block_p5_mmx); \ >- } else { \ >- xor_speed(&xor_block_8regs); \ >- xor_speed(&xor_block_8regs_p); \ >- xor_speed(&xor_block_32regs); \ >- xor_speed(&xor_block_32regs_p); \ >+ if (!cpu_has_hypervisor) \ >+ break; \ > } \ >+ xor_speed(&xor_block_8regs); \ >+ xor_speed(&xor_block_8regs_p); \ >+ xor_speed(&xor_block_32regs); \ >+ xor_speed(&xor_block_32regs_p); \ > } while (0) > > #endif /* _ASM_X86_XOR_32_H */ >--- 3.7-rc3-x86-xor.orig/arch/x86/include/asm/xor_64.h >+++ 3.7-rc3-x86-xor/arch/x86/include/asm/xor_64.h >@@ -9,10 +9,6 @@ static struct xor_block_template xor_blo > .do_5 = xor_sse_5, > }; > >- >-/* Also try the AVX routines */ >-#include <asm/xor_avx.h> >- >/* We force the use of the SSE xor block because it can write around >L2. > We may also be able to load into the L1 only depending on how the cpu > deals with a load to a line that is being prefetched. */ >@@ -22,6 +18,12 @@ do { \ > AVX_XOR_SPEED; \ > xor_speed(&xor_block_sse_pf64); \ > xor_speed(&xor_block_sse); \ >+ if (cpu_has_hypervisor) { \ >+ xor_speed(&xor_block_8regs); \ >+ xor_speed(&xor_block_8regs_p); \ >+ xor_speed(&xor_block_32regs); \ >+ xor_speed(&xor_block_32regs_p); \ >+ } \ > } while (0) > > #endif /* _ASM_X86_XOR_64_H */
-- Sent from my mobile phone. Please excuse brevity and lack of formatting.
| |