diff options
Diffstat (limited to 'src/basecmd.c')
| -rw-r--r-- | src/basecmd.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/src/basecmd.c b/src/basecmd.c index 2c9562b6..4902bd9d 100644 --- a/src/basecmd.c +++ b/src/basecmd.c @@ -191,15 +191,26 @@ command_get_status(uint32_t *args) } DECL_COMMAND_FLAGS(command_get_status, HF_IN_SHUTDOWN, "get_status"); +#define SUMSQ_BASE 256 +DECL_CONSTANT(STATS_SUMSQ_BASE, SUMSQ_BASE); + static void stats_task(void) { static uint32_t last, count, sumsq; uint32_t cur = sched_read_time(); - uint32_t diff = (cur - last) >> 8; + uint32_t diff = cur - last; last = cur; count++; - uint32_t nextsumsq = sumsq + diff*diff; + // Calculate sum of diff^2 - be careful of integer overflow + uint32_t nextsumsq; + if (diff <= 0xffff) { + nextsumsq = sumsq + DIV_ROUND_UP(diff * diff, SUMSQ_BASE); + } else if (diff <= 0xfffff) { + nextsumsq = sumsq + DIV_ROUND_UP(diff, SUMSQ_BASE) * diff; + } else { + nextsumsq = 0xffffffff; + } if (nextsumsq < sumsq) nextsumsq = 0xffffffff; sumsq = nextsumsq; |