From 50b926e439620c469565e8be0f28be78f5fca1ce Mon Sep 17 00:00:00 2001 From: Mike Galbraith Date: Mon, 4 Jan 2010 14:44:56 +0100 Subject: sched: Fix vmark regression on big machines SD_PREFER_SIBLING is set at the CPU domain level if power saving isn't enabled, leading to many cache misses on large machines as we traverse looking for an idle shared cache to wake to. Change the enabler of select_idle_sibling() to SD_SHARE_PKG_RESOURCES, and enable same at the sibling domain level. Reported-by: Lin Ming Signed-off-by: Mike Galbraith Signed-off-by: Peter Zijlstra LKML-Reference: <1262612696.15495.15.camel@marge.simson.net> Signed-off-by: Ingo Molnar --- include/linux/topology.h | 2 +- kernel/sched_fair.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/topology.h b/include/linux/topology.h index 57e63579bfd..5b81156780b 100644 --- a/include/linux/topology.h +++ b/include/linux/topology.h @@ -99,7 +99,7 @@ int arch_update_cpu_topology(void); | 1*SD_WAKE_AFFINE \ | 1*SD_SHARE_CPUPOWER \ | 0*SD_POWERSAVINGS_BALANCE \ - | 0*SD_SHARE_PKG_RESOURCES \ + | 1*SD_SHARE_PKG_RESOURCES \ | 0*SD_SERIALIZE \ | 0*SD_PREFER_SIBLING \ , \ diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 42ac3c9f66f..8fe7ee81c55 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1508,7 +1508,7 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag * If there's an idle sibling in this domain, make that * the wake_affine target instead of the current cpu. */ - if (tmp->flags & SD_PREFER_SIBLING) + if (tmp->flags & SD_SHARE_PKG_RESOURCES) target = select_idle_sibling(p, tmp, target); if (target >= 0) { -- cgit v1.2.3-18-g5258 From 6d558c3ac9b6508d26fd5cadccce51fc9d726b1c Mon Sep 17 00:00:00 2001 From: Yong Zhang Date: Mon, 11 Jan 2010 14:21:25 +0800 Subject: sched: Reassign prev and switch_count when reacquire_kernel_lock() fail Assume A->B schedule is processing, if B have acquired BKL before and it need reschedule this time. Then on B's context, it will go to need_resched_nonpreemptible for reschedule. But at this time, prev and switch_count are related to A. It's wrong and will lead to incorrect scheduler statistics. Signed-off-by: Yong Zhang Signed-off-by: Peter Zijlstra LKML-Reference: <2674af741001102238w7b0ddcadref00d345e2181d11@mail.gmail.com> Signed-off-by: Ingo Molnar --- kernel/sched.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/sched.c b/kernel/sched.c index c535cc4f642..4508fe7048b 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -5530,8 +5530,11 @@ need_resched_nonpreemptible: post_schedule(rq); - if (unlikely(reacquire_kernel_lock(current) < 0)) + if (unlikely(reacquire_kernel_lock(current) < 0)) { + prev = rq->curr; + switch_count = &prev->nivcsw; goto need_resched_nonpreemptible; + } preempt_enable_no_resched(); if (need_resched()) -- cgit v1.2.3-18-g5258