X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=lib%2Fgauss.c;h=f974490f72a512465a2ee3e534031418833da539;hp=cd8b6e3e491a8669b3d5cad6e92c80567d656acb;hb=8c5e96a4ee7004b2982b5d5247ecea1cb96bccb7;hpb=56d9fa4b8d4fa5166e3ec5dcdd37b5789b2cb01d diff --git a/lib/gauss.c b/lib/gauss.c index cd8b6e3e..f974490f 100644 --- a/lib/gauss.c +++ b/lib/gauss.c @@ -15,7 +15,7 @@ static int gauss_dev(struct gauss_state *gs) return 0; r = __rand(&gs->r); - vr = gs->stddev * (r / (FRAND_MAX + 1.0)); + vr = gs->stddev * (r / (FRAND32_MAX + 1.0)); return vr - gs->stddev / 2; } @@ -38,16 +38,27 @@ unsigned long long gauss_next(struct gauss_state *gs) sum += dev; } - return __hash_u64(sum) % gs->nranges; + if (!gs->disable_hash) + sum = __hash_u64(sum); + + return sum % gs->nranges; } -void gauss_init(struct gauss_state *gs, unsigned long nranges, unsigned int d, +void gauss_init(struct gauss_state *gs, unsigned long nranges, double dev, unsigned int seed) { memset(gs, 0, sizeof(*gs)); - init_rand_seed(&gs->r, seed); + init_rand_seed(&gs->r, seed, 0); gs->nranges = nranges; - gs->stddev = d; - if (gs->stddev > nranges / 2) - gs->stddev = nranges / 2; + + if (dev != 0.0) { + gs->stddev = ceil((double) (nranges * 100.0) / dev); + if (gs->stddev > nranges / 2) + gs->stddev = nranges / 2; + } +} + +void gauss_disable_hash(struct gauss_state *gs) +{ + gs->disable_hash = true; }