On 07/01/2015 02:49 AM, Christoffer Dall wrote: > On Wed, Jun 24, 2015 at 05:04:10PM -0700, Mario Smarduch wrote: >> Currently we save/restore fp/simd on each exit. Fist patch optimizes arm64 >> save/restore, we only do so on Guest access. hackbench and >> several lmbench tests show anywhere from 30% to above 50% optimzation >> achieved. >> >> In second patch 32-bit handler is updated to keep exit handling consistent >> with 64-bit code. > > 30-50% of what? The overhead or overall performance? Yes, so considering all exits to Host KVM anywhere from 30 to 50% didn't require an fp/simd switch. Anything else you like to see added here? > >> >> Changes since v1: >> - Addressed Marcs comments >> - Verified optimization improvements with lmbench and hackbench, updated >> commit message >> >> Changes since v2: >> - only for patch 2/2 >> - Reworked trapping to vfp access handler >> >> Changes since v3: >> - Only for patch 2/2 >> - Removed load_vcpu in switch_to_guest_vfp per Marcs comment >> - Got another chance to replace an unreferenced label with a comment >> >> >> Mario Smarduch (2): >> Optimize arm64 skip 30-50% vfp/simd save/restore on exits >> keep arm vfp/simd exit handling consistent with arm64 >> >> arch/arm/kvm/interrupts.S | 14 +++++++----- >> arch/arm64/include/asm/kvm_arm.h | 5 ++++- >> arch/arm64/kvm/hyp.S | 46 +++++++++++++++++++++++++++++++++++--- >> 3 files changed, 55 insertions(+), 10 deletions(-) >> >> -- >> 1.7.9.5 >> -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
