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Temporarily widen count for interrupt rate calculations on 32-bit archs

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If the interrupt count is very high (greater than ~42M), notably on one-shot
execution on long running systems, the intermediate multiplication step in the
rate calculation will overflow the width of a 32-bit architecture long (32
bits), causing the rest of the calculation to calculate with a truncated value,
and report very low rates (sometimes 0).

MFC after:	2 weeks
This commit is contained in:
Justin Hibbits 2018-02-08 05:18:30 +00:00
parent 354fce2869
commit fb3d972447
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=329013
1 changed files with 1 additions and 1 deletions
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2
usr.bin/vmstat/vmstat.c
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@ -1304,7 +1304,7 @@ print_intrcnts(unsigned long *intrcnts, unsigned long *old_intrcnts,
for (i = 0, intrcnt=intrcnts, old_intrcnt=old_intrcnts; i < nintr; i++) {
if (intrname[0] != '\0' && (*intrcnt != 0 || aflag)) {
count = *intrcnt - *old_intrcnt;
rate = (count * 1000 + period_ms / 2) / period_ms;
rate = ((uint64_t)count * 1000 + period_ms / 2) / period_ms;
xo_open_instance("interrupt");
xo_emit("{d:name/%-*s}{ket:name/%s} "
"{:total/%20lu} {:rate/%10lu}\n",