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;
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++)
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));
}
}
- /**
- * 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;