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authorDenis Lunev <den@sw.ru>2005-07-30 17:47:25 -0700
committerDavid S. Miller <davem@davemloft.net>2005-07-30 17:47:25 -0700
commitf0098f7863f814a5adc0b9cb271605d063cad7fa (patch)
tree7477022770edd99422586372147e9b0f48de4c63
parentdb44575f6fd55df6ff67ddd21f7ad5be5a741136 (diff)
downloadop-kernel-dev-f0098f7863f814a5adc0b9cb271605d063cad7fa.zip
op-kernel-dev-f0098f7863f814a5adc0b9cb271605d063cad7fa.tar.gz
[NET] Fix too aggressive backoff in dst garbage collection
The bug is evident when it is seen once. dst gc timer was backed off, when gc queue is not empty. But this means that timer quickly backs off, if at least one destination remains in use. Normally, the bug is invisible, because adding new dst entry to queue cancels the backoff. But it shots deadly with destination cache overflow when new destinations are not released for long time f.e. after an interface goes down. The fix is to cancel backoff when something was released. Signed-off-by: Denis Lunev <den@sw.ru> Signed-off-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/core/dst.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/net/core/dst.c b/net/core/dst.c
index fc434ad..334790d 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -45,6 +45,7 @@ static struct timer_list dst_gc_timer =
static void dst_run_gc(unsigned long dummy)
{
int delayed = 0;
+ int work_performed;
struct dst_entry * dst, **dstp;
if (!spin_trylock(&dst_lock)) {
@@ -52,9 +53,9 @@ static void dst_run_gc(unsigned long dummy)
return;
}
-
del_timer(&dst_gc_timer);
dstp = &dst_garbage_list;
+ work_performed = 0;
while ((dst = *dstp) != NULL) {
if (atomic_read(&dst->__refcnt)) {
dstp = &dst->next;
@@ -62,6 +63,7 @@ static void dst_run_gc(unsigned long dummy)
continue;
}
*dstp = dst->next;
+ work_performed = 1;
dst = dst_destroy(dst);
if (dst) {
@@ -86,9 +88,14 @@ static void dst_run_gc(unsigned long dummy)
dst_gc_timer_inc = DST_GC_MAX;
goto out;
}
- if ((dst_gc_timer_expires += dst_gc_timer_inc) > DST_GC_MAX)
- dst_gc_timer_expires = DST_GC_MAX;
- dst_gc_timer_inc += DST_GC_INC;
+ if (!work_performed) {
+ if ((dst_gc_timer_expires += dst_gc_timer_inc) > DST_GC_MAX)
+ dst_gc_timer_expires = DST_GC_MAX;
+ dst_gc_timer_inc += DST_GC_INC;
+ } else {
+ dst_gc_timer_inc = DST_GC_INC;
+ dst_gc_timer_expires = DST_GC_MIN;
+ }
dst_gc_timer.expires = jiffies + dst_gc_timer_expires;
#if RT_CACHE_DEBUG >= 2
printk("dst_total: %d/%d %ld\n",
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