Make p->numa_shared flip/flop less around unstable equilibriums, instead require a significant move in either direction to trigger 'dominantly shared accesses' versus 'dominantly private accesses' NUMA status.
Suggested-by: Rik van Riel <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Hugh Dickins <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> --- kernel/sched/fair.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 46d23c7..f3fb508 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1111,7 +1111,20 @@ static void task_numa_placement(struct task_struct *p) * we might want to consider a different equation below to reduce * the impact of a little private memory accesses. */ - shared = (total[0] >= total[1] / 2); + shared = p->numa_shared; + + if (shared < 0) { + shared = (total[0] >= total[1]); + } else if (shared == 0) { + /* If it was private before, make it harder to become shared: */ + if (total[0] >= total[1]*2) + shared = 1; + } else if (shared == 1 ) { + /* If it was shared before, make it harder to become private: */ + if (total[0]*2 <= total[1]) + shared = 0; + } + if (shared) p->ideal_cpu = sched_update_ideal_cpu_shared(p); else -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
