[patch 2/2] round_jiffies users

[patch 2/2] round_jiffies users

[Arjan van de Ven]

From: Arjan van de Ven <arjan@linux.intel.com>
Subject: round_jiffies users
CC: jgarzik@pobox.com
CC: netdev@vger.kernel.org

This patch introduces users of the round_jiffies() function.
These timers all were of the "about once a second" or "about once every X seconds" 
variety and several showed up in the "what wakes the cpu up" profiles that
the tickless patches provide.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>

Index: linux-2.6.19-rc1-git6/mm/slab.c
===================================================================
--- linux-2.6.19-rc1-git6.orig/mm/slab.c
+++ linux-2.6.19-rc1-git6/mm/slab.c
@@ -926,7 +926,7 @@ static void __devinit start_cpu_timer(in
 	if (keventd_up() && reap_work->func == NULL) {
 		init_reap_node(cpu);
 		INIT_WORK(reap_work, cache_reap, NULL);
-		schedule_delayed_work_on(cpu, reap_work, HZ + 3 * cpu);
+		schedule_delayed_work_on(cpu, reap_work, __round_jiffies_relative(HZ, cpu));
 	}
 }
 
@@ -3821,7 +3821,7 @@ static void cache_reap(void *unused)
 	if (!mutex_trylock(&cache_chain_mutex)) {
 		/* Give up. Setup the next iteration. */
 		schedule_delayed_work(&__get_cpu_var(reap_work),
-				      REAPTIMEOUT_CPUC);
+				      round_jiffies_relative(REAPTIMEOUT_CPUC));
 		return;
 	}
 
@@ -3867,7 +3867,8 @@ next:
 	next_reap_node();
 	refresh_cpu_vm_stats(smp_processor_id());
 	/* Set up the next iteration */
-	schedule_delayed_work(&__get_cpu_var(reap_work), REAPTIMEOUT_CPUC);
+	schedule_delayed_work(&__get_cpu_var(reap_work),
+		round_jiffies_relative(REAPTIMEOUT_CPUC));
 }
 
 #ifdef CONFIG_PROC_FS
Index: linux-2.6.19-rc1-git6/fs/jbd/transaction.c
===================================================================
--- linux-2.6.19-rc1-git6.orig/fs/jbd/transaction.c
+++ linux-2.6.19-rc1-git6/fs/jbd/transaction.c
@@ -53,7 +53,7 @@ get_transaction(journal_t *journal, tran
 	spin_lock_init(&transaction->t_handle_lock);
 
 	/* Set up the commit timer for the new transaction. */
-	journal->j_commit_timer.expires = transaction->t_expires;
+	journal->j_commit_timer.expires = round_jiffies(transaction->t_expires);
 	add_timer(&journal->j_commit_timer);
 
 	J_ASSERT(journal->j_running_transaction == NULL);
Index: linux-2.6.19-rc1-git6/drivers/ata/libata-scsi.c
===================================================================
--- linux-2.6.19-rc1-git6.orig/drivers/ata/libata-scsi.c
+++ linux-2.6.19-rc1-git6/drivers/ata/libata-scsi.c
@@ -3094,7 +3094,8 @@ void ata_scsi_hotplug(void *data)
 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
 		struct ata_device *dev = &ap->device[i];
 		if (ata_dev_enabled(dev) && !dev->sdev) {
-			queue_delayed_work(ata_aux_wq, &ap->hotplug_task, HZ);
+			queue_delayed_work(ata_aux_wq, &ap->hotplug_task,
+				round_jiffies_relative(HZ));
 			break;
 		}
 	}
Index: linux-2.6.19-rc1-git6/net/core/dst.c
===================================================================
--- linux-2.6.19-rc1-git6.orig/net/core/dst.c
+++ linux-2.6.19-rc1-git6/net/core/dst.c
@@ -99,7 +99,14 @@ static void dst_run_gc(unsigned long dum
 	printk("dst_total: %d/%d %ld\n",
 	       atomic_read(&dst_total), delayed,  dst_gc_timer_expires);
 #endif
-	mod_timer(&dst_gc_timer, jiffies + dst_gc_timer_expires);
+	/* if the next desired timer is more than 4 seconds in the future
+	 * then round the timer to whole seconds
+	 */
+	if (dst_gc_timer_expires > 4*HZ)
+		mod_timer(&dst_gc_timer,
+			round_jiffies(jiffies + dst_gc_timer_expires));
+	else
+		mod_timer(&dst_gc_timer, jiffies + dst_gc_timer_expires);
 
 out:
 	spin_unlock(&dst_lock);
Index: linux-2.6.19-rc1-git6/net/core/neighbour.c
===================================================================
--- linux-2.6.19-rc1-git6.orig/net/core/neighbour.c
+++ linux-2.6.19-rc1-git6/net/core/neighbour.c
@@ -695,7 +695,10 @@ next_elt:
 	if (!expire)
 		expire = 1;
 
- 	mod_timer(&tbl->gc_timer, now + expire);
+	if (expire>HZ)
+		mod_timer(&tbl->gc_timer, round_jiffies(now + expire));
+	else
+	 	mod_timer(&tbl->gc_timer, now + expire);
 
 	write_unlock(&tbl->lock);
 }
Index: linux-2.6.19-rc1-git6/net/sched/sch_generic.c
===================================================================
--- linux-2.6.19-rc1-git6.orig/net/sched/sch_generic.c
+++ linux-2.6.19-rc1-git6/net/sched/sch_generic.c
@@ -209,7 +209,7 @@ static void dev_watchdog(unsigned long a
 				       dev->name);
 				dev->tx_timeout(dev);
 			}
-			if (!mod_timer(&dev->watchdog_timer, jiffies + dev->watchdog_timeo))
+			if (!mod_timer(&dev->watchdog_timer, round_jiffies(jiffies + dev->watchdog_timeo)))
 				dev_hold(dev);
 		}
 	}
Index: linux-2.6.19-rc1-git6/drivers/net/e1000/e1000_main.c
===================================================================
--- linux-2.6.19-rc1-git6.orig/drivers/net/e1000/e1000_main.c
+++ linux-2.6.19-rc1-git6/drivers/net/e1000/e1000_main.c
@@ -483,7 +483,7 @@ e1000_up(struct e1000_adapter *adapter)
 
 	clear_bit(__E1000_DOWN, &adapter->flags);
 
-	mod_timer(&adapter->watchdog_timer, jiffies + 2 * HZ);
+	mod_timer(&adapter->watchdog_timer, round_jiffies(jiffies + 2 * HZ));
 	return 0;
 }
 
@@ -2493,7 +2493,7 @@ e1000_watchdog(unsigned long data)
 
 			netif_carrier_on(netdev);
 			netif_wake_queue(netdev);
-			mod_timer(&adapter->phy_info_timer, jiffies + 2 * HZ);
+			mod_timer(&adapter->phy_info_timer, round_jiffies(jiffies + 2 * HZ));
 			adapter->smartspeed = 0;
 		}
 	} else {
@@ -2503,7 +2503,7 @@ e1000_watchdog(unsigned long data)
 			DPRINTK(LINK, INFO, "NIC Link is Down\n");
 			netif_carrier_off(netdev);
 			netif_stop_queue(netdev);
-			mod_timer(&adapter->phy_info_timer, jiffies + 2 * HZ);
+			mod_timer(&adapter->phy_info_timer, round_jiffies(jiffies + 2 * HZ));
 
 			/* 80003ES2LAN workaround--
 			 * For packet buffer work-around on link down event;
@@ -2568,7 +2568,7 @@ e1000_watchdog(unsigned long data)
 		e1000_rar_set(&adapter->hw, adapter->hw.mac_addr, 0);
 
 	/* Reset the timer */
-	mod_timer(&adapter->watchdog_timer, jiffies + 2 * HZ);
+	mod_timer(&adapter->watchdog_timer, round_jiffies(jiffies + 2 * HZ));
 }
 
 #define E1000_TX_FLAGS_CSUM		0x00000001

Re: [patch 2/2] round_jiffies users

[Ingo Oeser]

Hi Arjan,

Arjan van de Ven wrote:
> Index: linux-2.6.19-rc1-git6/mm/slab.c
> ===================================================================
> --- linux-2.6.19-rc1-git6.orig/mm/slab.c
> +++ linux-2.6.19-rc1-git6/mm/slab.c
> @@ -926,7 +926,7 @@ static void __devinit start_cpu_timer(in
>  	if (keventd_up() && reap_work->func == NULL) {
>  		init_reap_node(cpu);
>  		INIT_WORK(reap_work, cache_reap, NULL);
> -		schedule_delayed_work_on(cpu, reap_work, HZ + 3 * cpu);
> +		schedule_delayed_work_on(cpu, reap_work, __round_jiffies_relative(HZ, cpu));
>  	}
>  }
>  

Did you changed the behavior by intention?
You seem to miss the factor "3" here. This hunk should read:

--- linux-2.6.19-rc1-git6.orig/mm/slab.c
+++ linux-2.6.19-rc1-git6/mm/slab.c
@@ -926,7 +926,7 @@ static void __devinit start_cpu_timer(in
 	if (keventd_up() && reap_work->func == NULL) {
 		init_reap_node(cpu);
 		INIT_WORK(reap_work, cache_reap, NULL);
-		schedule_delayed_work_on(cpu, reap_work, HZ + 3 * cpu);
+		schedule_delayed_work_on(cpu, reap_work, __round_jiffies_relative(HZ, 3 * cpu));
 	}
 }
 

In case you apply it:

Signed-off-by: Ingo Oese <netdev@axxeo.de>


Regards

Ingo Oeser

Re: [patch 2/2] round_jiffies users

[Arjan van de Ven]

On Tue, 2006-10-10 at 18:47 +0200, Ingo Oeser wrote:
> Hi Arjan,
> 
> Arjan van de Ven wrote:
> > Index: linux-2.6.19-rc1-git6/mm/slab.c
> > ===================================================================
> > --- linux-2.6.19-rc1-git6.orig/mm/slab.c
> > +++ linux-2.6.19-rc1-git6/mm/slab.c
> > @@ -926,7 +926,7 @@ static void __devinit start_cpu_timer(in
> >  	if (keventd_up() && reap_work->func == NULL) {
> >  		init_reap_node(cpu);
> >  		INIT_WORK(reap_work, cache_reap, NULL);
> > -		schedule_delayed_work_on(cpu, reap_work, HZ + 3 * cpu);
> > +		schedule_delayed_work_on(cpu, reap_work, __round_jiffies_relative(HZ, cpu));
> >  	}
> >  }
> >  
> 
> Did you changed the behavior by intention?
> You seem to miss the factor "3" here. This hunk should read:

Hi,

actually.. not really; the __round_jiffies_relative function just takes
a CPU number, and internally takes care of spreading things around based
on CPU number (eg it does the *3 internally); it's cleaner that way, the
callers don't need to bother by how much to spread for each cpu etc
etc... So the patch is correct as is.


Greetings,
   Arjan van de Ven

Re: [patch 2/2] round_jiffies users

[Paul Dickson]

On Tue, 10 Oct 2006 18:04:23 +0200, Arjan van de Ven wrote:

> +			mod_timer(&adapter->phy_info_timer, round_jiffies(jiffies + 2 * HZ));

Shouldn't round_jiffies_relative be used for some of these, a la:

  +			mod_timer(&adapter->phy_info_timer, round_jiffies_relative(2 * HZ));

	-Paul

Re: [patch 2/2] round_jiffies users

[Arjan van de Ven]

Paul Dickson wrote:
> On Tue, 10 Oct 2006 18:04:23 +0200, Arjan van de Ven wrote:
> 
>> +			mod_timer(&adapter->phy_info_timer, round_jiffies(jiffies + 2 * HZ));
> 
> Shouldn't round_jiffies_relative be used for some of these, a la:
> 
>   +			mod_timer(&adapter->phy_info_timer, round_jiffies_relative(2 * HZ));
> 

mod_timer() takes an absolute jiffies value as argument, so... no :)