* [PATCH] ipv4 : igmp : optimize timer modify logic in igmp_mod_timer()
@ 2011-11-23 15:26 Jun Zhao
2011-11-23 15:42 ` Eric Dumazet
0 siblings, 1 reply; 3+ messages in thread
From: Jun Zhao @ 2011-11-23 15:26 UTC (permalink / raw)
To: davem; +Cc: netdev, Jun Zhao
When timer is pending and expires less-than-or-equal-to new delay,
we need not used del_timer()/add_timer().
Signed-off-by: Jun Zhao <mypopydev@gmail.com>
---
net/ipv4/igmp.c | 12 ++++++------
1 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index c7472ef..50d06c5 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -215,14 +215,14 @@ static void igmp_mod_timer(struct ip_mc_list *im, int max_delay)
{
spin_lock_bh(&im->lock);
im->unsolicit_count = 0;
- if (del_timer(&im->timer)) {
- if ((long)(im->timer.expires-jiffies) < max_delay) {
- add_timer(&im->timer);
- im->tm_running = 1;
- spin_unlock_bh(&im->lock);
+ if (timer_pending(&im->timer)) {
+ if (time_before_eq(im->timer.expires, (jiffies + max_delay))) {
+ spin_lock_bh(&im->lock);
return;
+ } else {
+ del_timer(&im->timer);
+ atomic_dec(&im->refcnt);
}
- atomic_dec(&im->refcnt);
}
igmp_start_timer(im, max_delay);
spin_unlock_bh(&im->lock);
--
1.7.2.5
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] ipv4 : igmp : optimize timer modify logic in igmp_mod_timer()
2011-11-23 15:26 [PATCH] ipv4 : igmp : optimize timer modify logic in igmp_mod_timer() Jun Zhao
@ 2011-11-23 15:42 ` Eric Dumazet
2011-11-23 15:44 ` Jun Zhao
0 siblings, 1 reply; 3+ messages in thread
From: Eric Dumazet @ 2011-11-23 15:42 UTC (permalink / raw)
To: Jun Zhao; +Cc: davem, netdev
Le mercredi 23 novembre 2011 à 23:26 +0800, Jun Zhao a écrit :
> When timer is pending and expires less-than-or-equal-to new delay,
> we need not used del_timer()/add_timer().
>
> Signed-off-by: Jun Zhao <mypopydev@gmail.com>
> ---
> net/ipv4/igmp.c | 12 ++++++------
> 1 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
> index c7472ef..50d06c5 100644
> --- a/net/ipv4/igmp.c
> +++ b/net/ipv4/igmp.c
> @@ -215,14 +215,14 @@ static void igmp_mod_timer(struct ip_mc_list *im, int max_delay)
> {
> spin_lock_bh(&im->lock);
> im->unsolicit_count = 0;
> - if (del_timer(&im->timer)) {
> - if ((long)(im->timer.expires-jiffies) < max_delay) {
> - add_timer(&im->timer);
> - im->tm_running = 1;
> - spin_unlock_bh(&im->lock);
> + if (timer_pending(&im->timer)) {
> + if (time_before_eq(im->timer.expires, (jiffies + max_delay))) {
> + spin_lock_bh(&im->lock);
And you actually tested this patch ?
> return;
> + } else {
> + del_timer(&im->timer);
> + atomic_dec(&im->refcnt);
> }
> - atomic_dec(&im->refcnt);
> }
> igmp_start_timer(im, max_delay);
> spin_unlock_bh(&im->lock);
Not sure why you want to optimize this very rare function call, risking
adding bugs in it.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] ipv4 : igmp : optimize timer modify logic in igmp_mod_timer()
2011-11-23 15:42 ` Eric Dumazet
@ 2011-11-23 15:44 ` Jun Zhao
0 siblings, 0 replies; 3+ messages in thread
From: Jun Zhao @ 2011-11-23 15:44 UTC (permalink / raw)
To: Eric Dumazet; +Cc: davem, netdev
On Wed, 2011-11-23 at 16:42 +0100, Eric Dumazet wrote:
> Le mercredi 23 novembre 2011 à 23:26 +0800, Jun Zhao a écrit :
> > When timer is pending and expires less-than-or-equal-to new delay,
> > we need not used del_timer()/add_timer().
> >
> > Signed-off-by: Jun Zhao <mypopydev@gmail.com>
> > ---
> > net/ipv4/igmp.c | 12 ++++++------
> > 1 files changed, 6 insertions(+), 6 deletions(-)
> >
> > diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
> > index c7472ef..50d06c5 100644
> > --- a/net/ipv4/igmp.c
> > +++ b/net/ipv4/igmp.c
> > @@ -215,14 +215,14 @@ static void igmp_mod_timer(struct ip_mc_list *im, int max_delay)
> > {
> > spin_lock_bh(&im->lock);
> > im->unsolicit_count = 0;
> > - if (del_timer(&im->timer)) {
> > - if ((long)(im->timer.expires-jiffies) < max_delay) {
> > - add_timer(&im->timer);
> > - im->tm_running = 1;
> > - spin_unlock_bh(&im->lock);
> > + if (timer_pending(&im->timer)) {
> > + if (time_before_eq(im->timer.expires, (jiffies + max_delay))) {
> > + spin_lock_bh(&im->lock);
>
> And you actually tested this patch ?
Sorry for this mistake. :(. spin_lock_bh -> spin_unlock_bh
>
> > return;
> > + } else {
> > + del_timer(&im->timer);
> > + atomic_dec(&im->refcnt);
> > }
> > - atomic_dec(&im->refcnt);
> > }
> > igmp_start_timer(im, max_delay);
> > spin_unlock_bh(&im->lock);
>
>
> Not sure why you want to optimize this very rare function call, risking
> adding bugs in it.
>
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2011-11-23 15:45 UTC | newest]
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2011-11-23 15:26 [PATCH] ipv4 : igmp : optimize timer modify logic in igmp_mod_timer() Jun Zhao
2011-11-23 15:42 ` Eric Dumazet
2011-11-23 15:44 ` Jun Zhao
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