Files
TempleOS-Rijn/Demo/Lectures/Mem/Uncached.CPP
T
2018-09-08 21:47:01 +02:00

47 lines
985 B
C++

// Requires $LK,"::/Demo/Lectures/Mem/Mem2Meg.CPP"$.
Cd(__DIR__);;
#include "Mem2Meg"
#define SAMPLE_SIZE 100000
U0 TimeIns()
{
I64 i,start,end;
I64 *cached_I64=MAlloc(sizeof(I64)),
shared_blks,*uncached_I64;
CBlkPool *bp;
CHeapCtrl *hc;
"$$RED$$Now, this demo seems broken, perhaps,\n"
"because I run in a virtual machine.$$FG$$\n\n";
CPURep;
shared_blks=1;
bp=Mem2MegUncachedAlloc(&shared_blks);
hc=HeapCtrlBPInit(bp,shared_blks<<12);
uncached_I64=MAlloc(sizeof(I64),hc);
//Measure cached time
start=GetTSC;
for (i=0;i<SAMPLE_SIZE;i++)
*cached_I64=i;
end=GetTSC;
" Cached Cycles: %10,d\n",end-start;
//Measure uncached time
start=GetTSC;
for (i=0;i<SAMPLE_SIZE;i++)
*uncached_I64=i;
end=GetTSC;
"Uncached Cycles: %10,d\n",end-start;
"$$GREEN$$The difference is even greater\n"
"because the loop overhead was not subtracted.$$FG$$\n\n";
Free(cached_I64);
Free(uncached_I64);
Mem2MegFree(bp,shared_blks);
}
TimeIns;