On Mon, Oct 31, 2011 at 04:28:33PM +0100, Oleg Nesterov wrote: > On 10/31, Frantisek Hrbata wrote: > > > > My understanding is that we may just change the type of points variable from int > > to long and keep the current imho clearer(better readable) computation. There > > should not be an overflow on 32bit and there is a plenty of space for 64bit. > > If you like this solution better I will post the patch as v2. > > Up to maintainer, but personally I think the simple s/int/long/ looks better. > Everything like get_mm_*/nr_ptes returns long. Agreed. I will post v2 with the int => long change. > > Anyway good catch. Imho stable needs the fix too. > > Cosmetic nit, > > > - points = get_mm_rss(p->mm) + p->mm->nr_ptes; > > - points += get_mm_counter(p->mm, MM_SWAPENTS); > > + points = (int)((get_mm_rss(p->mm) + get_mm_counter(p->mm, MM_SWAPENTS) + > ^^^^^ > > Why do we need the explicit typecast? It buys nothing and looks a bit confusing. You are right, it's not needed. I just wanted to make the cast more visible, but some kind of comment would be probably better here. > > And, if you prefer "int", perhaps something like > > - points *= 1000; > - points /= totalpages; > + /* avoid the possible overflow */ > + points = points * 1000L / totalpages; > > looks a bit more readable with the same effect. But I won't insist, this is > up to you and David. Sure, this looks much better than the one line expression in the patch I sent. If David or others decide to not go with the int=>long change I think we should use this. > > Oleg. > Many thanks Oleg. -- Frantisek Hrbata -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>