[NET]: user of the jiffies rounding code: Networking

This patch introduces users of the round_jiffies() function in the
networking code.

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.  Some timers are
highly dynamic based on network load; but even on low activity systems
they still show up so the rounding is done only in cases of low
activity, allowing higher frequency timers in the high activity case.

The various hardware watchdogs are an obvious case; they run every 2
seconds but aren't otherwise specific of exactly when they need to
run.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/dst.c b/net/core/dst.c
index 836ec66069254752c7ca2b9db0a597419dd758a2..1a53fb39b7e008efa67709bcd4ac984426e064df 100644 (file)
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -99,7 +99,14 @@ static void dst_run_gc(unsigned long dummy)
        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);

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 9e26f38ea6e58fd26e2af3e78be1914050e26341..054d46493d2be47b4ab9b4a467dd8f08052b5bf3 100644 (file)
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -696,7 +696,10 @@ 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);
 }

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index bc116bd6937c01ffba6adcb142161f38b05b7e8c..3b6e6a7809278f69769ca764f65df928d0e023d3 100644 (file)
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -209,7 +209,7 @@ static void dev_watchdog(unsigned long arg)
                                       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);
                }
        }