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	ArnimS	2008-02-15 , 01:38
	Posts: 1,107 \| Thanked: 720 times \| Joined on Mar 2007 @ Germany	#124

Here's a fairly typical oprofile run for recent dosbox
running wing commander, vga, cycles 1600, frameskip 5 sound is somewhat sputtery. The breakdown was pretty surprising to me - due to high frameskip and dirty buffer technology vga and screen blits accounts for only a few percent of the cpu use.

Code:

CPU: ARM V6 PMU, speed 0 MHz (estimated)
Counted CPU_CYCLES events (clock cycles counter) with a unit mask of 0x00 (No unit mask) count 100000
samples  %        app name                 symbol name
790837   37.7594  dosbox                   CPU_Core_Simple_Run()
205133    9.7943  dosbox                   OPL2::YM3812UpdateOne(int, short*, int)
141333    6.7481  dosbox                   mem_writew(unsigned int, unsigned short)
139735    6.6718  no-vmlinux               (no symbols)
139255    6.6489  dosbox                   mem_readw(unsigned int)
80063     3.8227  dosbox                   VGA_ChainedVGA_Handler::writew(unsigned int, unsigned int)
48412     2.3115  dosbox                   DoString(STRING_OP)
41582     1.9854  dosbox                   FillFlags()
36618     1.7484  oprofiled                (no symbols)
24928     1.1902  dosbox                   CPU_Push16(unsigned int)
23724     1.1327  libSDL-1.2.so.0.7.1      (no symbols)
23586     1.1261  libc-2.5.so              (no symbols)
21747     1.0383  dosbox                   get_CF()
21385     1.0210  dosbox                   get_ZF()
20214     0.9651  libm-2.5.so              (no symbols)
18982     0.9063  dosbox                   EA_16_06_n()
17843     0.8519  dosbox                   EA_16_46_n()
14050     0.6708  dosbox                   EA_16_87_n()
12277     0.5862  esd                      __udivsi3
11886     0.5675  dosbox                   mem_readb(unsigned int)
11750     0.5610  esd                      mix_stereo_16s_to_stereo_32s_sv
10450     0.4989  libpthread-2.5.so        (no symbols)
9641      0.4603  dosbox                   CPU_Pop16()
9593      0.4580  dosbox                   vga_read_p3da(unsigned int, unsigned int)
9429      0.4502  dosbox                   CPU_SetSegGeneral(SegNames, unsigned int)
9387      0.4482  dosbox                   CPU_IO_Exception(unsigned int, unsigned int)
8710      0.4159  dosbox                   read_latch(unsigned int, unsigned int)
8610      0.4111  dosbox                   CPU_CALL(bool, unsigned int, unsigned int, unsigned int)
8609      0.4110  dosbox                   RENDER_StartLineHandler(void const*)
8531      0.4073  dosbox                   Normal1x_8_16_R(void const*)
8445      0.4032  esd                      mix_players
7688      0.3671  dosbox                   PIC_RunQueue()
7181      0.3429  dosbox                   counter_latch(unsigned int)
6856      0.3273  dosbox                   IO_ReadB(unsigned int)

What does it all mean? Well it does give us an indication of why sound blaster emulation requires reducing CPU cycles so much.

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