Subject: sched: revert load_balance_monitor()
The following commit causes a number of serious regressions:
commit 6b2d7700266b9402e12824e11e0099ae6a4a6a79
Author: Srivatsa Vaddagiri <[EMAIL PROTECTED]>
Date: Fri Jan 25 21:08:00 2008 +0100
sched: group scheduler, fix fairness of cpu bandwidth allocation for task
groups
Namely:
- very frequent wakeups on SMP, reported by PowerTop users.
- cacheline trashing on (large) SMP
- some latencies larger than 500ms
While there is a mergeable patch to fix the latter, the former issues
are IMHO not fixable in a manner suitable for .25 (we're at -rc3 now).
Hence I propose to revert this patch and try again for .26.
( minimal revert - leaves most of the code present, just removes the activation
and sysctl interface ).
Signed-off-by: Peter Zijlstra <[EMAIL PROTECTED]>
CC: Srivatsa Vaddagiri <[EMAIL PROTECTED]>
---
include/linux/sched.h | 4 ----
kernel/sched.c | 15 ---------------
kernel/sysctl.c | 18 ------------------
3 files changed, 37 deletions(-)
Index: linux-2.6/include/linux/sched.h
===================================================================
--- linux-2.6.orig/include/linux/sched.h
+++ linux-2.6/include/linux/sched.h
@@ -1541,10 +1541,6 @@ extern unsigned int sysctl_sched_child_r
extern unsigned int sysctl_sched_features;
extern unsigned int sysctl_sched_migration_cost;
extern unsigned int sysctl_sched_nr_migrate;
-#if defined(CONFIG_FAIR_GROUP_SCHED) && defined(CONFIG_SMP)
-extern unsigned int sysctl_sched_min_bal_int_shares;
-extern unsigned int sysctl_sched_max_bal_int_shares;
-#endif
int sched_nr_latency_handler(struct ctl_table *table, int write,
struct file *file, void __user *buffer, size_t *length,
Index: linux-2.6/kernel/sched.c
===================================================================
--- linux-2.6.orig/kernel/sched.c
+++ linux-2.6/kernel/sched.c
@@ -7083,21 +7083,6 @@ void __init sched_init_smp(void)
if (set_cpus_allowed(current, non_isolated_cpus) < 0)
BUG();
sched_init_granularity();
-
-#ifdef CONFIG_FAIR_GROUP_SCHED
- if (nr_cpu_ids == 1)
- return;
-
- lb_monitor_task = kthread_create(load_balance_monitor, NULL,
- "group_balance");
- if (!IS_ERR(lb_monitor_task)) {
- lb_monitor_task->flags |= PF_NOFREEZE;
- wake_up_process(lb_monitor_task);
- } else {
- printk(KERN_ERR "Could not create load balance monitor thread"
- "(error = %ld) \n", PTR_ERR(lb_monitor_task));
- }
-#endif
}
#else
void __init sched_init_smp(void)
Index: linux-2.6/kernel/sysctl.c
===================================================================
--- linux-2.6.orig/kernel/sysctl.c
+++ linux-2.6/kernel/sysctl.c
@@ -311,24 +311,6 @@ static struct ctl_table kern_table[] = {
.mode = 0644,
.proc_handler = &proc_dointvec,
},
-#if defined(CONFIG_FAIR_GROUP_SCHED) && defined(CONFIG_SMP)
- {
- .ctl_name = CTL_UNNUMBERED,
- .procname = "sched_min_bal_int_shares",
- .data = &sysctl_sched_min_bal_int_shares,
- .maxlen = sizeof(unsigned int),
- .mode = 0644,
- .proc_handler = &proc_dointvec,
- },
- {
- .ctl_name = CTL_UNNUMBERED,
- .procname = "sched_max_bal_int_shares",
- .data = &sysctl_sched_max_bal_int_shares,
- .maxlen = sizeof(unsigned int),
- .mode = 0644,
- .proc_handler = &proc_dointvec,
- },
-#endif
#endif
{
.ctl_name = CTL_UNNUMBERED,
--
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