On 9/28/18 3:27 PM, Jeff Moyer wrote: > Hi, > > If you use a very large I/O size (1G in this instance), and also specify > the verify option, fio will hang, using up 100% cpu, for ever and ever. > The problem is that __fill_random_buf_percentage does math that > overflows the size of an unsigned int. Fixing that gets fio to > terminate as expected. > > Here is the job file which showed the problem: > > [global] > ioengine=dev-dax > direct=0 > filename=/dev/dax0.0 > verify=crc32c > bs=1G > [write] > rw=write > runtime=5 > [read] > stonewall > rw=read > runtime=5 > > Reported-by: sujith_pandel@xxxxxxxx > Signed-off-by: Jeff Moyer <jmoyer@xxxxxxxxxx> > > diff --git a/lib/rand.c b/lib/rand.c > index 46ffe4fb..99846a8d 100644 > --- a/lib/rand.c > +++ b/lib/rand.c > @@ -156,7 +156,7 @@ void __fill_random_buf_percentage(unsigned long seed, void *buf, > /* > * Fill random chunk > */ > - this_len = (segment * (100 - percentage)) / 100; > + this_len = ((unsigned long long)segment * (100 - percentage)) / 100; > if (this_len > len) > this_len = len; Thanks Jeff, applied. -- Jens Axboe
