On Mon, Nov 8, 2010 at 7:14 AM, Johannes Weiner <hannes@xxxxxxxxxxx> wrote: > Folding the per-cpu counters can yield a negative value in case of > accounting races between CPUs. > > When collecting the dirty info, the code would read those sums into an > unsigned variable and then check for it being negative, which can not > work. > > Instead, fold the counters into a signed local variable, make the > check, and only then assign it. > > This way, the function signals correctly when there are insane values > instead of leaking them out to the caller. > > Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> Reviewed-by: Minchan Kim <minchan.kim@xxxxxxxxx> -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>