Try a better VOSF run-time performance check heuristic.

This commit is contained in:
gbeauche 2004-06-26 16:26:07 +00:00
parent 380d4f294e
commit 6482f7b7a6

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@ -189,30 +189,33 @@ static uint32 page_extend(uint32 size)
* Check if VOSF acceleration is profitable on this platform
*/
const int VOSF_PROFITABLE_THRESHOLD = 8000; // 8 ms, aka (60 Hz / 2) for work processing
const int VOSF_PROFITABLE_TRIES = 3; // Make 3 attempts for full screen update
const int VOSF_PROFITABLE_THRESHOLD = 16667; // 60 Hz
static bool video_vosf_profitable(void)
{
int64 durations[VOSF_PROFITABLE_TRIES];
int mean_duration = 0;
for (int i = 0; i < VOSF_PROFITABLE_TRIES; i++) {
uint64 start = GetTicks_usec();
for (int i = 0; i < mainBuffer.pageCount; i++) {
uint8 *addr = (uint8 *)(mainBuffer.memStart + (i * mainBuffer.pageSize));
memset(addr, 0, mainBuffer.pageSize); // Trigger Screen_fault_handler()
for (int p = 0; p < mainBuffer.pageCount; p++) {
uint8 *addr = (uint8 *)(mainBuffer.memStart + (p * mainBuffer.pageSize));
addr[0] = 0; // Trigger Screen_fault_handler()
}
int64 duration = GetTicks_usec() - start;
mean_duration += duration;
durations[i] = duration;
uint64 end = GetTicks_usec();
const int diff = end - start;
D(bug("Triggered %d screen faults in %ld usec\n", mainBuffer.pageCount, diff));
if (diff > (VOSF_PROFITABLE_THRESHOLD * (frame_skip + 1)))
return false;
// Reset VOSF variables to initial state
PFLAG_CLEAR_ALL;
mainBuffer.dirty = false;
if (vm_protect((char *)mainBuffer.memStart, mainBuffer.memLength, VM_PAGE_READ) != 0)
return false;
mainBuffer.dirty = false;
return true;
}
mean_duration /= VOSF_PROFITABLE_TRIES;
D(bug("Triggered %d screen faults in %ld usec on average\n", mainBuffer.pageCount, mean_duration));
return (mean_duration < (VOSF_PROFITABLE_THRESHOLD * (frame_skip ? frame_skip : 1)));
}