From ede9e383e514bbfff9aae501bc438c95f7bf5211 Mon Sep 17 00:00:00 2001 From: avg Date: Mon, 19 Dec 2011 20:01:21 +0000 Subject: [PATCH 082/175] ule: ensure that batch timeshare threads are scheduled fairly With the previous code, if the range of priorities for timeshare batch threads was greater than RQ_NQS, then the threads with low priorities in the part of the range above RQ_NQS would be scheduled to the run-queues as if they had high priorities at the beginning of the range. In other words, threads with a nice level of +N could be scheduled as if they had a nice level of -M. Reported by: George Mitchell Reviewed by: jhb Tested by: George Mitchell (earlier version) MFC after: 1 week git-svn-id: http://svn.freebsd.org/base/head@228718 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f (cherry picked from commit 8ded2b4336be2b3d394c82b9bb9aaebc2c462c5f) Signed-off-by: Xin Li --- sys/kern/sched_ule.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/sys/kern/sched_ule.c b/sys/kern/sched_ule.c index 31d3d11..1d34342 100644 --- a/sys/kern/sched_ule.c +++ b/sys/kern/sched_ule.c @@ -125,6 +125,7 @@ static struct td_sched td_sched0; */ #define PRI_TIMESHARE_RANGE (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE + 1) #define PRI_INTERACT_RANGE ((PRI_TIMESHARE_RANGE - SCHED_PRI_NRESV) / 2) +#define PRI_BATCH_RANGE (PRI_TIMESHARE_RANGE - PRI_INTERACT_RANGE) #define PRI_MIN_INTERACT PRI_MIN_TIMESHARE #define PRI_MAX_INTERACT (PRI_MIN_TIMESHARE + PRI_INTERACT_RANGE - 1) @@ -416,7 +417,6 @@ sched_shouldpreempt(int pri, int cpri, int remote) return (0); } -#define TS_RQ_PPQ (((PRI_MAX_BATCH - PRI_MIN_BATCH) + 1) / RQ_NQS) /* * Add a thread to the actual run-queue. Keeps transferable counts up to * date with what is actually on the run-queue. Selects the correct @@ -449,7 +449,7 @@ tdq_runq_add(struct tdq *tdq, struct thread *td, int flags) * realtime. Use the whole queue to represent these values. */ if ((flags & (SRQ_BORROWING|SRQ_PREEMPTED)) == 0) { - pri = (pri - PRI_MIN_BATCH) / TS_RQ_PPQ; + pri = RQ_NQS * (pri - PRI_MIN_BATCH) / PRI_BATCH_RANGE; pri = (pri + tdq->tdq_idx) % RQ_NQS; /* * This effectively shortens the queue by one so we -- 1.7.9.4