Update autotune engine

pull/352/head
jsteube 8 years ago
parent 63f5ecf9d7
commit c901935843

@ -2865,7 +2865,22 @@ static void autotune (hc_device_param_t *device_param)
u32 kernel_accel = kernel_accel_min;
u32 kernel_loops = kernel_loops_min;
// init some fake words
// in this case the user specified a fixed -u and -n on the commandline
// no way to tune anything
// but we need to run a few caching rounds
if ((kernel_loops_min == kernel_loops_max) && (kernel_accel_min == kernel_accel_max))
{
try_run (device_param, kernel_accel, kernel_loops);
try_run (device_param, kernel_accel, kernel_loops);
try_run (device_param, kernel_accel, kernel_loops);
try_run (device_param, kernel_accel, kernel_loops);
return;
}
// from here it's clear we are allowed to autotune
// so let's init some fake words
const u32 kernel_power_max = device_param->device_processors * device_param->kernel_threads * kernel_accel_max;
@ -2883,35 +2898,31 @@ static void autotune (hc_device_param_t *device_param)
run_kernel_amp (device_param, kernel_power_max);
}
// begin actual testing
#define VERIFIER_CNT 1
double exec_ms_final = try_run (device_param, kernel_accel, kernel_loops);
// first find out highest kernel-loops that stays below target_ms
if ((kernel_loops_min == kernel_loops_max) || (kernel_accel_min == kernel_accel_max))
if (kernel_loops_min < kernel_loops_max)
{
// we do this in case the user specified a fixed -u and -n on the commandline
// so we have a cached kernel for benchmark
try_run (device_param, kernel_accel, kernel_loops);
try_run (device_param, kernel_accel, kernel_loops);
try_run (device_param, kernel_accel, kernel_loops);
try_run (device_param, kernel_accel, kernel_loops);
try_run (device_param, kernel_accel, kernel_loops);
}
// first find out highest kernel-loops that stays below target_ms
for (kernel_loops = kernel_loops_max; kernel_loops > kernel_loops_min; kernel_loops >>= 1)
{
double exec_ms = try_run (device_param, kernel_accel_min, kernel_loops);
#define STEPS_CNT 10
for (int i = 0; i < VERIFIER_CNT; i++)
{
double exec_ms_v = try_run (device_param, kernel_accel_min, kernel_loops);
for (kernel_loops = kernel_loops_max; kernel_loops > kernel_loops_min; kernel_loops >>= 1)
{
double exec_ms = try_run (device_param, kernel_accel_min, kernel_loops);
exec_ms = MIN (exec_ms, exec_ms_v);
}
if (exec_ms < target_ms) break;
if (exec_ms < target_ms) break;
}
}
// now the same for kernel-accel but with the new kernel-loops from previous loop set
#define STEPS_CNT 10
if (kernel_accel_min < kernel_accel_max)
{
for (int i = 0; i < STEPS_CNT; i++)
@ -2923,59 +2934,79 @@ static void autotune (hc_device_param_t *device_param)
double exec_ms = try_run (device_param, kernel_accel_try, kernel_loops);
if (exec_ms > target_ms) break;
for (int i = 0; i < VERIFIER_CNT; i++)
{
double exec_ms_v = try_run (device_param, kernel_accel_try, kernel_loops);
exec_ms_final = exec_ms;
exec_ms = MIN (exec_ms, exec_ms_v);
}
if (exec_ms > target_ms) break;
kernel_accel = kernel_accel_try;
}
}
// there's a chance that we have a fixed kernel_loops but not a fixed kernel_accel
// in such a case the above function would not create any change
// we'll use the runtime to find out if we're allow to do last improvement
// at this point we want to know the actual runtime for the following reason:
// we need a reference for the balancing loop following up, and this
// the balancing loop can have an effect that the creates a new opportunity, for example:
// if the target is 95 ms and the current runtime is 48ms the above loop
// stopped the execution because the previous exec_ms was > 95ms
// due to the rebalance it's possible that the runtime reduces from 48ms to 47ms
// and this creates the possibility to double the workload -> 47 * 2 = 95ms, which is < 96ms
double exec_ms_pre_final = try_run (device_param, kernel_accel, kernel_loops);
for (int i = 0; i < VERIFIER_CNT; i++)
{
double exec_ms_pre_final_v = try_run (device_param, kernel_accel, kernel_loops);
exec_ms_pre_final = MIN (exec_ms_pre_final, exec_ms_pre_final_v);
}
if (exec_ms_final > 0)
if ((kernel_loops_min < kernel_loops_max) && (kernel_accel_min < kernel_accel_max))
{
if ((exec_ms_final * 2) <= target_ms)
for (u32 f = 2; f < 1024; f++)
{
const double exec_left = target_ms / exec_ms_final;
const u32 kernel_accel_try = kernel_accel * f;
const u32 kernel_loops_try = kernel_loops / f;
if (kernel_accel_try > kernel_accel_max) break;
if (kernel_loops_try < kernel_loops_min) break;
const double accel_left = kernel_accel_max / kernel_accel;
double exec_ms = try_run (device_param, kernel_accel_try, kernel_loops_try);
const int exec_accel_min = MIN (exec_left, accel_left); // we want that to be int
for (int i = 0; i < VERIFIER_CNT; i++)
{
double exec_ms_v = try_run (device_param, kernel_accel_try, kernel_loops_try);
exec_ms = MIN (exec_ms, exec_ms_v);
}
if (exec_accel_min >= 2)
if (exec_ms < exec_ms_pre_final)
{
kernel_accel *= exec_accel_min;
exec_ms_pre_final = exec_ms;
kernel_accel = kernel_accel_try;
kernel_loops = kernel_loops_try;
}
}
}
// balancing the workload turns out to be very efficient
const double exec_left = target_ms / exec_ms_pre_final;
if (kernel_loops_min != kernel_loops_max)
{
const u32 kernel_power_balance = kernel_accel * kernel_loops;
u32 sqrtv;
const double accel_left = kernel_accel_max / kernel_accel;
for (sqrtv = 1; sqrtv < 0x100000; sqrtv++)
{
if ((sqrtv * sqrtv) >= kernel_power_balance) break;
}
const int exec_accel_min = MIN (exec_left, accel_left); // we want that to be int
const u32 kernel_accel_try = sqrtv;
const u32 kernel_loops_try = sqrtv;
if (exec_accel_min >= 2)
{
// this is safe to not overflow kernel_accel_max because of accel_left
if ((kernel_accel_try <= kernel_accel_max) && (kernel_loops_try >= kernel_loops_min))
{
kernel_accel = kernel_accel_try;
kernel_loops = kernel_loops_try;
}
kernel_accel *= exec_accel_min;
}
// reset fake words
// reset them fake words
memset (device_param->pws_buf, 0, kernel_power_max * sizeof (pw_t));
@ -14314,22 +14345,6 @@ int main (int argc, char **argv)
}
}
/**
* some algorithms need a special kernel-accel
*/
if (hash_mode == 8900)
{
device_param->kernel_accel_min = 1;
device_param->kernel_accel_max = 64;
}
if (hash_mode == 9300)
{
device_param->kernel_accel_min = 1;
device_param->kernel_accel_max = 64;
}
u32 kernel_accel_min = device_param->kernel_accel_min;
u32 kernel_accel_max = device_param->kernel_accel_max;

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