| Message ID | 20200310170746.GD79873@mtj.duckdns.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [block/for-5.6-fixes] blk-iocost: fix incorrect vtime comparison in iocg_is_idle() | expand |
On 3/10/20 11:07 AM, Tejun Heo wrote: > vtimes may wrap and time_before/after64() should be used to determine > whether a given vtime is before or after another. iocg_is_idle() was > incorrectly using plain "<" comparison do determine whether done_vtime > is before vtime. Here, the only thing we're interested in is whether > done_vtime matches vtime which indicates that there's nothing in > flight. Let's test for inequality instead. Applied, thanks.
diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 27ca68621137..9a599cc28c29 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -1318,7 +1318,7 @@ static bool iocg_is_idle(struct ioc_gq *iocg) return false; /* is something in flight? */ - if (atomic64_read(&iocg->done_vtime) < atomic64_read(&iocg->vtime)) + if (atomic64_read(&iocg->done_vtime) != atomic64_read(&iocg->vtime)) return false; return true;
vtimes may wrap and time_before/after64() should be used to determine whether a given vtime is before or after another. iocg_is_idle() was incorrectly using plain "<" comparison do determine whether done_vtime is before vtime. Here, the only thing we're interested in is whether done_vtime matches vtime which indicates that there's nothing in flight. Let's test for inequality instead. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost") Cc: stable@vger.kernel.org # v5.4+ --- block/blk-iocost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)