Re: [PATCH RFC 2/2] [x86] Optimize copy_page by re-arranging instruction sequence and saving register

From: George Spelvin
Date: Mon Oct 15 2012 - 01:15:11 EST

Just for everyone's information, here's the updated benchmark code on
the same Phenom. The REP MOVSQ code is indeed much faster.

vendor_id : AuthenticAMD
cpu family : 16
model : 2
model name : AMD Phenom(tm) 9850 Quad-Core Processor
stepping : 3
microcode : 0x1000083
cpu MHz : 2500.210
cache size : 512 KB
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm 3dnowext 3dnow constant_tsc rep_good nopl nonstop_tsc extd_apicid pni monitor cx16 popcnt lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs hw_pstate npt lbrv svm_lock
bogomips : 5000.42
TLB size : 1024 4K pages
clflush size : 64
cache_alignment : 64

copy_page_org copy_page_new REP MOVSQ
TPT: Len 4096, alignment 0/ 0: 708 758 611
TPT: Len 4096, alignment 0/ 0: 672 758 611
TPT: Len 4096, alignment 0/ 0: 708 758 611
TPT: Len 4096, alignment 0/ 0: 708 758 611
TPT: Len 4096, alignment 0/ 0: 708 758 611
copy_page_org copy_page_new REP MOVSQ
TPT: Len 4096, alignment 0/ 0: 694 759 611
TPT: Len 4096, alignment 0/ 0: 672 758 611
TPT: Len 4096, alignment 0/ 0: 708 758 611
TPT: Len 4096, alignment 0/ 0: 708 759 611
TPT: Len 4096, alignment 0/ 0: 708 757 611
copy_page_org copy_page_new REP MOVSQ
TPT: Len 4096, alignment 0/ 0: 697 758 611
TPT: Len 4096, alignment 0/ 0: 708 758 611
TPT: Len 4096, alignment 0/ 0: 708 758 611
TPT: Len 4096, alignment 0/ 0: 708 758 611
TPT: Len 4096, alignment 0/ 0: 708 757 611
copy_page_org copy_page_new REP MOVSQ
TPT: Len 4096, alignment 0/ 0: 703 758 612
TPT: Len 4096, alignment 0/ 0: 709 758 611
TPT: Len 4096, alignment 0/ 0: 709 757 611
TPT: Len 4096, alignment 0/ 0: 709 759 613
TPT: Len 4096, alignment 0/ 0: 709 759 611
copy_page_org copy_page_new REP MOVSQ
TPT: Len 4096, alignment 0/ 0: 669 758 613
TPT: Len 4096, alignment 0/ 0: 671 758 611
TPT: Len 4096, alignment 0/ 0: 708 758 611
TPT: Len 4096, alignment 0/ 0: 708 758 611
TPT: Len 4096, alignment 0/ 0: 708 758 613
copy_page_org copy_page_new REP MOVSQ
TPT: Len 4096, alignment 0/ 0: 679 758 612
TPT: Len 4096, alignment 0/ 0: 671 758 612
TPT: Len 4096, alignment 0/ 0: 684 759 612
TPT: Len 4096, alignment 0/ 0: 709 759 613
TPT: Len 4096, alignment 0/ 0: 709 759 611
copy_page_org copy_page_new REP MOVSQ
TPT: Len 4096, alignment 0/ 0: 682 758 612
TPT: Len 4096, alignment 0/ 0: 673 758 613
TPT: Len 4096, alignment 0/ 0: 704 759 613
TPT: Len 4096, alignment 0/ 0: 709 758 613
TPT: Len 4096, alignment 0/ 0: 709 758 611
copy_page_org copy_page_new REP MOVSQ
TPT: Len 4096, alignment 0/ 0: 669 759 611
TPT: Len 4096, alignment 0/ 0: 671 759 611
TPT: Len 4096, alignment 0/ 0: 709 759 613
TPT: Len 4096, alignment 0/ 0: 709 759 613
TPT: Len 4096, alignment 0/ 0: 708 759 613
copy_page_org copy_page_new REP MOVSQ
TPT: Len 4096, alignment 0/ 0: 668 759 612
TPT: Len 4096, alignment 0/ 0: 709 759 612
TPT: Len 4096, alignment 0/ 0: 709 759 612
TPT: Len 4096, alignment 0/ 0: 709 759 612
TPT: Len 4096, alignment 0/ 0: 709 759 612
copy_page_org copy_page_new REP MOVSQ
TPT: Len 4096, alignment 0/ 0: 694 758 611
TPT: Len 4096, alignment 0/ 0: 671 759 611
TPT: Len 4096, alignment 0/ 0: 708 759 611
TPT: Len 4096, alignment 0/ 0: 708 759 611
TPT: Len 4096, alignment 0/ 0: 708 759 613
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