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pkt_sched: sch_qfq: fix the update of eligible-group sets

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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.

Signed-off-by: Paolo Valente <paolo.valente@unimore.it>
Reviewed-by: Fabio Checconi <fchecconi@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Paolo Valente 2013-03-05 08:04:58 +00:00 committed by David S. Miller
parent 9b99b7e90b
commit 624b85fb96
1 changed files with 1 additions and 1 deletions
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2
net/sched/sch_qfq.c
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@ -821,7 +821,7 @@ static void qfq_make_eligible(struct qfq_sched *q)
unsigned long old_vslot = q->oldV >> q->min_slot_shift;
if (vslot != old_vslot) {
unsigned long mask = (1UL << fls(vslot ^ old_vslot)) - 1;
unsigned long mask = (1ULL << fls(vslot ^ old_vslot)) - 1;
qfq_move_groups(q, mask, IR, ER);
qfq_move_groups(q, mask, IB, EB);
}