On Sun, Sep 22 2013, Tejun Heo wrote: > (cc'ing Jens) > > Hello, > > On Fri, Sep 13, 2013 at 09:20:45AM -0700, Anatol Pomozov wrote: > > Hi, Tejun > > > > On Fri, Aug 30, 2013 at 10:52 AM, Anatol Pomozov > > <anatol.pomozov@xxxxxxxxx> wrote: > > > 'samples' is 64bit operant, but do_div() second parameter is 32. > > > do_div silently truncates high 32 bits and calculated result > > > is invalid. > > > > > > In case if low 32bit of 'samples' are zeros then do_div() produces > > > kernel crash. > > > > > > Signed-off-by: Anatol Pomozov <anatol.pomozov@xxxxxxxxx> > > > --- > > > block/cfq-iosched.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c > > > index d5bbdcf..c410752 100644 > > > --- a/block/cfq-iosched.c > > > +++ b/block/cfq-iosched.c > > > @@ -1803,7 +1803,7 @@ static u64 cfqg_prfill_avg_queue_size(struct seq_file *sf, > > > > > > if (samples) { > > > v = blkg_stat_read(&cfqg->stats.avg_queue_size_sum); > > > - do_div(v, samples); > > > + v = div64_u64(v, samples); > > > } > > > __blkg_prfill_u64(sf, pd, v); > > > return 0; > > > > what do you think about this patch? > > Sorry about the delay. Was traveling. > > Acked-by: Tejun Heo <tj@xxxxxxxxxx> > > blkcg patches are routed through Jens's block tree but I haven't been > able to get hold of Jens lately. Jens? Sorry, been a bit crazy on my end. Will queue it up for 3.12, thanks. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html