> Between two invocations of make_eligible, the system virtual time may > happen to grow enough that, in its binary representation, a bit with > higher order than 31 flips. This happens especially with > TSO/GSO. Before this fix, the mask used in make_eligible was computed > as (1UL<<index_of_last_flipped_bit)-1, whose value is well defined on > a 64-bit architecture, because index_of_flipped_bit <= 63, but is in > general undefined on a 32-bit architecture if index_of_flipped_bit > 31. > The fix just replaces 1UL with 1ULL. ... > - unsigned long mask = (1UL << fls(vslot ^ old_vslot)) - 1; > + unsigned long mask = (1ULL << fls(vslot ^ old_vslot)) - 1;
I'm not sure you really want to be doing 64bit shifts on 32 bit systems just to generate ~0ul. probably worth a conditional. David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/