2159197d6677 ("sched/core: Enable increased load resolution on 64-bit kernels")exposed yet another miscalculation in calc_cfs_shares: MIN_SHARES is unscaled, and must thus be scaled before being manipulated against "shares" amounts. Signed-off-by: Samuel Thibault <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: [email protected] Fixes: 2159197d6677 ("sched/core: Enable increased load resolution on 64-bit kernels") --- This should be backported to 4.7 and 4.8 to fix scheduling priorities miscalculations diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 6559d19..be84f72 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2657,8 +2657,8 @@ static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg) if (tg_weight) shares /= tg_weight; - if (shares < MIN_SHARES) - shares = MIN_SHARES; + if (shares < scale_load(MIN_SHARES)) + shares = scale_load(MIN_SHARES); if (shares > tg->shares) shares = tg->shares;
