| Message ID | 1275929761.2545.159.camel@edumazet-laptop |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | David Miller |
| Headers | show |
Eric Dumazet wrote: ... > [PATCH net-next-2.6] pkt_sched: gen_kill_estimator() rcu fixes > > gen_kill_estimator() API is fundamentaly wrong, since caller should make > sure an RCU grace period is respected before freeing bstats or lock. > > This was partially addressed in commit 5d944c640b4 (gen_estimator: > deadlock fix), but same problem exist for all gen_kill_estimator() > users. > > Change its name to gen_kill_estimator_rcu() and change all callers to > use RCU grace period before freeing bstats container. > > As a bonus, est_lock rwlock can be killed for good. > > Special thanks to Changli Gao for commenting on a previous patch, this > made this bug clear to me. > Actually, I guess, Changli meant the bug introduced by your previous patch by removing the est_lock. With this lock (and your commit 5d944) bstats (and API) seem "fundamentaly" safe. Jarek P. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Le mardi 08 juin 2010 à 12:15 +0000, Jarek Poplawski a écrit : > > Actually, I guess, Changli meant the bug introduced by your previous > patch by removing the est_lock. With this lock (and your commit 5d944) > bstats (and API) seem "fundamentaly" safe. > Sorry, I have no idea of what you want to say, I cant find commit 5d944. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Jun 08, 2010 at 02:27:32PM +0200, Eric Dumazet wrote: > Le mardi 08 juin 2010 ?? 12:15 +0000, Jarek Poplawski a écrit : > > > > > Actually, I guess, Changli meant the bug introduced by your previous > > patch by removing the est_lock. With this lock (and your commit 5d944) > > bstats (and API) seem "fundamentaly" safe. > > > > Sorry, I have no idea of what you want to say, I cant find commit 5d944. > Sorry, I meant the commit mentioned in your changelog which was quoted. > This was partially addressed in commit 5d944c640b4 (gen_estimator: > deadlock fix), but same problem exist for all gen_kill_estimator() > users. Jarek P. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Jarek Poplawski wrote, On 06/08/2010 02:40 PM: > On Tue, Jun 08, 2010 at 02:27:32PM +0200, Eric Dumazet wrote: >> Le mardi 08 juin 2010 ?? 12:15 +0000, Jarek Poplawski a écrit : >> >>> Actually, I guess, Changli meant the bug introduced by your previous >>> patch by removing the est_lock. With this lock (and your commit 5d944) >>> bstats (and API) seem "fundamentaly" safe. >>> >> Sorry, I have no idea of what you want to say, I cant find commit 5d944. >> > > Sorry, I meant the commit mentioned in your changelog which was quoted. > >> This was partially addressed in commit 5d944c640b4 (gen_estimator: >> deadlock fix), but same problem exist for all gen_kill_estimator() >> users. In case it's still unclear, I wanted to say that IMHO this patch's title and changelog are misleading because most of its content are est_lock to RCU changes - not fixes. >> [PATCH net-next-2.6] pkt_sched: gen_kill_estimator() rcu fixes >> >> gen_kill_estimator() API is fundamentaly wrong, since caller should make >> sure an RCU grace period is respected before freeing bstats or lock. Freeing bstats doesn't currently require RCU protection. Jarek P. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Le mardi 08 juin 2010 à 21:29 +0200, Jarek Poplawski a écrit : > Jarek Poplawski wrote, On 06/08/2010 02:40 PM: > > > On Tue, Jun 08, 2010 at 02:27:32PM +0200, Eric Dumazet wrote: > >> Le mardi 08 juin 2010 ?? 12:15 +0000, Jarek Poplawski a écrit : > >> > >>> Actually, I guess, Changli meant the bug introduced by your previous > >>> patch by removing the est_lock. With this lock (and your commit 5d944) > >>> bstats (and API) seem "fundamentaly" safe. > >>> > >> Sorry, I have no idea of what you want to say, I cant find commit 5d944. > >> > > > > Sorry, I meant the commit mentioned in your changelog which was quoted. > > > >> This was partially addressed in commit 5d944c640b4 (gen_estimator: > >> deadlock fix), but same problem exist for all gen_kill_estimator() > >> users. > > In case it's still unclear, I wanted to say that IMHO this patch's > title and changelog are misleading because most of its content are > est_lock to RCU changes - not fixes. > ... > >> [PATCH net-next-2.6] pkt_sched: gen_kill_estimator() rcu fixes > >> > >> gen_kill_estimator() API is fundamentaly wrong, since caller should make > >> sure an RCU grace period is respected before freeing bstats or lock. > > Freeing bstats doesn't currently require RCU protection. > > Jarek P. So what ? No changes needed ? I am really lost by your comments Jarek. Maybe you could provide an alternative patch, so that we can make some progress ? -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Jun 08, 2010 at 09:45:29PM +0200, Eric Dumazet wrote: > Le mardi 08 juin 2010 ?? 21:29 +0200, Jarek Poplawski a écrit : > > Jarek Poplawski wrote, On 06/08/2010 02:40 PM: > > > > > On Tue, Jun 08, 2010 at 02:27:32PM +0200, Eric Dumazet wrote: > > >> Le mardi 08 juin 2010 ?? 12:15 +0000, Jarek Poplawski a écrit : > > >> > > >>> Actually, I guess, Changli meant the bug introduced by your previous > > >>> patch by removing the est_lock. With this lock (and your commit 5d944) > > >>> bstats (and API) seem "fundamentaly" safe. > > >>> > > >> Sorry, I have no idea of what you want to say, I cant find commit 5d944. > > >> > > > > > > Sorry, I meant the commit mentioned in your changelog which was quoted. > > > > > >> This was partially addressed in commit 5d944c640b4 (gen_estimator: > > >> deadlock fix), but same problem exist for all gen_kill_estimator() > > >> users. > > > > In case it's still unclear, I wanted to say that IMHO this patch's > > title and changelog are misleading because most of its content are > > est_lock to RCU changes - not fixes. > > > > ... > > > >> [PATCH net-next-2.6] pkt_sched: gen_kill_estimator() rcu fixes > > >> > > >> gen_kill_estimator() API is fundamentaly wrong, since caller should make > > >> sure an RCU grace period is respected before freeing bstats or lock. > > > > Freeing bstats doesn't currently require RCU protection. > > > > Jarek P. > > So what ? No changes needed ? Such a changelog is a documentation for future, just like this one, crucial for this suject: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0929c2dd83317813425b937fbc0041013b8685ff There is no reason to make people (our?) life harder with describing unexistent bugs. > > I am really lost by your comments Jarek. > > Maybe you could provide an alternative patch, so that we can make some > progress ? > No, I only meant fixing the title and changelog if you have any problem with separating it for two parts. Jarek P. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> Such a changelog is a documentation for future, just like this one, > crucial for this suject: > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0929c2dd83317813425b937fbc0041013b8685ff > > There is no reason to make people (our?) life harder with describing > unexistent bugs. > Now you are telling me there is no bug, and I am lying ? > > > > I am really lost by your comments Jarek. > > > > Maybe you could provide an alternative patch, so that we can make some > > progress ? > > > > No, I only meant fixing the title and changelog if you have any problem > with separating it for two parts. I am suggesting you rewrite this Changelog, as being part of the patch, since I still miss your point, sorry, I must be very dumb tonight. Then, add your Signed-off-by. This is normal iterative process. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Jun 08, 2010 at 10:52:34PM +0200, Eric Dumazet wrote: > > > Such a changelog is a documentation for future, just like this one, > > crucial for this suject: > > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0929c2dd83317813425b937fbc0041013b8685ff > > > > There is no reason to make people (our?) life harder with describing > > unexistent bugs. > > > > Now you are telling me there is no bug, and I am lying ? > I didn't question freeing stats_lock (great catch BTW!). > > > > > > I am really lost by your comments Jarek. > > > > > > Maybe you could provide an alternative patch, so that we can make some > > > progress ? > > > > > > > No, I only meant fixing the title and changelog if you have any problem > > with separating it for two parts. > > I am suggesting you rewrite this Changelog, as being part of the patch, > since I still miss your point, sorry, I must be very dumb tonight. > > Then, add your Signed-off-by. > > This is normal iterative process. > No understado - no Englisch ;-) Sorry, Jarek P. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/net/act_api.h b/include/net/act_api.h index c05fd71..bab385f 100644 --- a/include/net/act_api.h +++ b/include/net/act_api.h @@ -20,6 +20,7 @@ struct tcf_common { struct gnet_stats_queue tcfc_qstats; struct gnet_stats_rate_est tcfc_rate_est; spinlock_t tcfc_lock; + struct rcu_head tcfc_rcu; }; #define tcf_next common.tcfc_next #define tcf_index common.tcfc_index @@ -32,6 +33,7 @@ struct tcf_common { #define tcf_qstats common.tcfc_qstats #define tcf_rate_est common.tcfc_rate_est #define tcf_lock common.tcfc_lock +#define tcf_rcu common.tcfc_rcu struct tcf_police { struct tcf_common common; diff --git a/include/net/gen_stats.h b/include/net/gen_stats.h index fa15771..3545696 100644 --- a/include/net/gen_stats.h +++ b/include/net/gen_stats.h @@ -40,7 +40,7 @@ extern int gnet_stats_finish_copy(struct gnet_dump *d); extern int gen_new_estimator(struct gnet_stats_basic_packed *bstats, struct gnet_stats_rate_est *rate_est, spinlock_t *stats_lock, struct nlattr *opt); -extern void gen_kill_estimator(struct gnet_stats_basic_packed *bstats, +extern void gen_kill_estimator_rcu(struct gnet_stats_basic_packed *bstats, struct gnet_stats_rate_est *rate_est); extern int gen_replace_estimator(struct gnet_stats_basic_packed *bstats, struct gnet_stats_rate_est *rate_est, diff --git a/include/net/netfilter/xt_rateest.h b/include/net/netfilter/xt_rateest.h index ddbf37e..5e14277 100644 --- a/include/net/netfilter/xt_rateest.h +++ b/include/net/netfilter/xt_rateest.h @@ -9,6 +9,7 @@ struct xt_rateest { struct gnet_estimator params; struct gnet_stats_rate_est rstats; struct gnet_stats_basic_packed bstats; + struct rcu_head rcu; }; extern struct xt_rateest *xt_rateest_lookup(const char *name); diff --git a/net/core/gen_estimator.c b/net/core/gen_estimator.c index cf8e703..bd06b4a 100644 --- a/net/core/gen_estimator.c +++ b/net/core/gen_estimator.c @@ -102,9 +102,6 @@ struct gen_estimator_head static struct gen_estimator_head elist[EST_MAX_INTERVAL+1]; -/* Protects against NULL dereference */ -static DEFINE_RWLOCK(est_lock); - /* Protects against soft lockup during large deletion */ static struct rb_root est_root = RB_ROOT; @@ -115,29 +112,25 @@ static void est_timer(unsigned long arg) rcu_read_lock(); list_for_each_entry_rcu(e, &elist[idx].list, list) { - u64 nbytes; - u64 brate; - u32 npackets; - u32 rate; + struct gnet_stats_basic_packed *bstats; spin_lock(e->stats_lock); - read_lock(&est_lock); - if (e->bstats == NULL) - goto skip; - - nbytes = e->bstats->bytes; - npackets = e->bstats->packets; - brate = (nbytes - e->last_bytes)<<(7 - idx); - e->last_bytes = nbytes; - e->avbps += (brate >> e->ewma_log) - (e->avbps >> e->ewma_log); - e->rate_est->bps = (e->avbps+0xF)>>5; - - rate = (npackets - e->last_packets)<<(12 - idx); - e->last_packets = npackets; - e->avpps += (rate >> e->ewma_log) - (e->avpps >> e->ewma_log); - e->rate_est->pps = (e->avpps+0x1FF)>>10; -skip: - read_unlock(&est_lock); + bstats = rcu_dereference(e->bstats); + if (bstats) { + u64 nbytes = ACCESS_ONCE(bstats->bytes); + u32 npackets = ACCESS_ONCE(bstats->packets); + u64 brate = (nbytes - e->last_bytes)<<(7 - idx); + u32 rate; + + e->last_bytes = nbytes; + e->avbps += (brate >> e->ewma_log) - (e->avbps >> e->ewma_log); + e->rate_est->bps = (e->avbps+0xF)>>5; + + rate = (npackets - e->last_packets)<<(12 - idx); + e->last_packets = npackets; + e->avpps += (rate >> e->ewma_log) - (e->avpps >> e->ewma_log); + e->rate_est->pps = (e->avpps+0x1FF)>>10; + } spin_unlock(e->stats_lock); } @@ -255,15 +248,18 @@ static void __gen_kill_estimator(struct rcu_head *head) } /** - * gen_kill_estimator - remove a rate estimator + * gen_kill_estimator_rcu - remove a rate estimator * @bstats: basic statistics * @rate_est: rate estimator statistics * * Removes the rate estimator specified by &bstats and &rate_est. * - * NOTE: Called under rtnl_mutex + * NOTES: + * Called under rtnl_mutex + * Because est_timer() requirements (RCU protection), caller + * should respect an RCU grace period before freeing bstats */ -void gen_kill_estimator(struct gnet_stats_basic_packed *bstats, +void gen_kill_estimator_rcu(struct gnet_stats_basic_packed *bstats, struct gnet_stats_rate_est *rate_est) { struct gen_estimator *e; @@ -271,15 +267,13 @@ void gen_kill_estimator(struct gnet_stats_basic_packed *bstats, while ((e = gen_find_node(bstats, rate_est))) { rb_erase(&e->node, &est_root); - write_lock_bh(&est_lock); - e->bstats = NULL; - write_unlock_bh(&est_lock); + rcu_assign_pointer(e->bstats, NULL); list_del_rcu(&e->list); call_rcu(&e->e_rcu, __gen_kill_estimator); } } -EXPORT_SYMBOL(gen_kill_estimator); +EXPORT_SYMBOL(gen_kill_estimator_rcu); /** * gen_replace_estimator - replace rate estimator configuration @@ -297,7 +291,7 @@ int gen_replace_estimator(struct gnet_stats_basic_packed *bstats, struct gnet_stats_rate_est *rate_est, spinlock_t *stats_lock, struct nlattr *opt) { - gen_kill_estimator(bstats, rate_est); + gen_kill_estimator_rcu(bstats, rate_est); return gen_new_estimator(bstats, rate_est, stats_lock, opt); } EXPORT_SYMBOL(gen_replace_estimator); diff --git a/net/netfilter/xt_RATEEST.c b/net/netfilter/xt_RATEEST.c index 69c01e1..55747cd 100644 --- a/net/netfilter/xt_RATEEST.c +++ b/net/netfilter/xt_RATEEST.c @@ -60,13 +60,18 @@ struct xt_rateest *xt_rateest_lookup(const char *name) } EXPORT_SYMBOL_GPL(xt_rateest_lookup); +static void xt_rateeset_free_rcu(struct rcu_head *head) +{ + kfree(container_of(head, struct xt_rateest, rcu)); +} + void xt_rateest_put(struct xt_rateest *est) { mutex_lock(&xt_rateest_mutex); if (--est->refcnt == 0) { hlist_del(&est->list); - gen_kill_estimator(&est->bstats, &est->rstats); - kfree(est); + gen_kill_estimator_rcu(&est->bstats, &est->rstats); + call_rcu(&est->rcu, xt_rateeset_free_rcu); } mutex_unlock(&xt_rateest_mutex); } @@ -179,6 +184,7 @@ static int __init xt_rateest_tg_init(void) static void __exit xt_rateest_tg_fini(void) { xt_unregister_target(&xt_rateest_tg_reg); + rcu_barrier(); /* Wait for completion of call_rcu()'s */ } diff --git a/net/sched/act_api.c b/net/sched/act_api.c index 972378f..597b260 100644 --- a/net/sched/act_api.c +++ b/net/sched/act_api.c @@ -26,6 +26,11 @@ #include <net/act_api.h> #include <net/netlink.h> +static void tcf_common_free_rcu(struct rcu_head *head) +{ + kfree(container_of(head, struct tcf_common, tcfc_rcu)); +} + void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo) { unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask); @@ -36,9 +41,9 @@ void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo) write_lock_bh(hinfo->lock); *p1p = p->tcfc_next; write_unlock_bh(hinfo->lock); - gen_kill_estimator(&p->tcfc_bstats, + gen_kill_estimator_rcu(&p->tcfc_bstats, &p->tcfc_rate_est); - kfree(p); + call_rcu(&p->tcfc_rcu, tcf_common_free_rcu); return; } } diff --git a/net/sched/act_police.c b/net/sched/act_police.c index 654f73d..c3afcba 100644 --- a/net/sched/act_police.c +++ b/net/sched/act_police.c @@ -97,6 +97,11 @@ nla_put_failure: goto done; } +static void tcf_police_free_rcu(struct rcu_head *head) +{ + kfree(container_of(head, struct tcf_police, tcf_rcu)); +} + static void tcf_police_destroy(struct tcf_police *p) { unsigned int h = tcf_hash(p->tcf_index, POL_TAB_MASK); @@ -107,13 +112,13 @@ static void tcf_police_destroy(struct tcf_police *p) write_lock_bh(&police_lock); *p1p = p->tcf_next; write_unlock_bh(&police_lock); - gen_kill_estimator(&p->tcf_bstats, - &p->tcf_rate_est); + gen_kill_estimator_rcu(&p->tcf_bstats, + &p->tcf_rate_est); if (p->tcfp_R_tab) qdisc_put_rtab(p->tcfp_R_tab); if (p->tcfp_P_tab) qdisc_put_rtab(p->tcfp_P_tab); - kfree(p); + call_rcu(&p->tcf_rcu, tcf_police_free_rcu); return; } } @@ -397,6 +402,7 @@ static void __exit police_cleanup_module(void) { tcf_unregister_action(&act_police_ops); + rcu_barrier(); /* Wait for completion of call_rcu()'s */ } module_init(police_init_module); diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c index 28c01ef..d61b3b3 100644 --- a/net/sched/sch_cbq.c +++ b/net/sched/sch_cbq.c @@ -140,6 +140,7 @@ struct cbq_class int filters; struct cbq_class *defaults[TC_PRIO_MAX+1]; + struct rcu_head rcu; }; struct cbq_sched_data @@ -1671,6 +1672,11 @@ static unsigned long cbq_get(struct Qdisc *sch, u32 classid) return 0; } +static void cbq_class_free_rcu(struct rcu_head *head) +{ + kfree(container_of(head, struct cbq_class, rcu)); +} + static void cbq_destroy_class(struct Qdisc *sch, struct cbq_class *cl) { struct cbq_sched_data *q = qdisc_priv(sch); @@ -1680,9 +1686,9 @@ static void cbq_destroy_class(struct Qdisc *sch, struct cbq_class *cl) tcf_destroy_chain(&cl->filter_list); qdisc_destroy(cl->q); qdisc_put_rtab(cl->R_tab); - gen_kill_estimator(&cl->bstats, &cl->rate_est); + gen_kill_estimator_rcu(&cl->bstats, &cl->rate_est); if (cl != &q->link) - kfree(cl); + call_rcu(&cl->rcu, cbq_class_free_rcu); } static void @@ -2066,6 +2072,7 @@ static int __init cbq_module_init(void) static void __exit cbq_module_exit(void) { unregister_qdisc(&cbq_qdisc_ops); + rcu_barrier(); /* Wait for completion of call_rcu()'s */ } module_init(cbq_module_init) module_exit(cbq_module_exit) diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c index b74046a..f0d5aae 100644 --- a/net/sched/sch_drr.c +++ b/net/sched/sch_drr.c @@ -31,6 +31,7 @@ struct drr_class { u32 quantum; u32 deficit; + struct rcu_head rcu; }; struct drr_sched { @@ -136,11 +137,16 @@ static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid, return 0; } +static void drr_class_free_rcu(struct rcu_head *head) +{ + kfree(container_of(head, struct drr_class, rcu)); +} + static void drr_destroy_class(struct Qdisc *sch, struct drr_class *cl) { - gen_kill_estimator(&cl->bstats, &cl->rate_est); + gen_kill_estimator_rcu(&cl->bstats, &cl->rate_est); qdisc_destroy(cl->qdisc); - kfree(cl); + call_rcu(&cl->rcu, drr_class_free_rcu); } static int drr_delete_class(struct Qdisc *sch, unsigned long arg) @@ -522,6 +528,7 @@ static int __init drr_init(void) static void __exit drr_exit(void) { unregister_qdisc(&drr_qdisc_ops); + rcu_barrier(); /* Wait for completion of call_rcu()'s */ } module_init(drr_init); diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index d20fcd2..22120d4 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -632,7 +632,7 @@ void qdisc_destroy(struct Qdisc *qdisc) qdisc_put_stab(qdisc->stab); #endif - gen_kill_estimator(&qdisc->bstats, &qdisc->rate_est); + gen_kill_estimator_rcu(&qdisc->bstats, &qdisc->rate_est); if (ops->reset) ops->reset(qdisc); if (ops->destroy) @@ -643,7 +643,7 @@ void qdisc_destroy(struct Qdisc *qdisc) kfree_skb(qdisc->gso_skb); /* - * gen_estimator est_timer() might access qdisc->q.lock, + * gen_estimator est_timer() might access qdisc->q.lock or bstats * wait a RCU grace period before freeing qdisc. */ call_rcu(&qdisc->rcu_head, qdisc_rcu_free); diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c index abd904b..c433aa8 100644 --- a/net/sched/sch_hfsc.c +++ b/net/sched/sch_hfsc.c @@ -174,6 +174,7 @@ struct hfsc_class unsigned long cl_vtperiod; /* vt period sequence number */ unsigned long cl_parentperiod;/* parent's vt period sequence number*/ unsigned long cl_nactive; /* number of active children */ + struct rcu_head rcu; }; struct hfsc_sched @@ -1111,6 +1112,11 @@ hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid, return 0; } +static void hfsc_class_free_rcu(struct rcu_head *head) +{ + kfree(container_of(head, struct hfsc_class, rcu)); +} + static void hfsc_destroy_class(struct Qdisc *sch, struct hfsc_class *cl) { @@ -1118,9 +1124,9 @@ hfsc_destroy_class(struct Qdisc *sch, struct hfsc_class *cl) tcf_destroy_chain(&cl->filter_list); qdisc_destroy(cl->qdisc); - gen_kill_estimator(&cl->bstats, &cl->rate_est); + gen_kill_estimator_rcu(&cl->bstats, &cl->rate_est); if (cl != &q->root) - kfree(cl); + call_rcu(&cl->rcu, hfsc_class_free_rcu); } static int @@ -1742,6 +1748,7 @@ static void __exit hfsc_cleanup(void) { unregister_qdisc(&hfsc_qdisc_ops); + rcu_barrier(); /* Wait for completion of call_rcu()'s */ } MODULE_LICENSE("GPL"); diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c index 0b52b8d..b7b5e29 100644 --- a/net/sched/sch_htb.c +++ b/net/sched/sch_htb.c @@ -123,6 +123,7 @@ struct htb_class { psched_tdiff_t mbuffer; /* max wait time */ long tokens, ctokens; /* current number of tokens */ psched_time_t t_c; /* checkpoint time */ + struct rcu_head rcu; }; struct htb_sched { @@ -1190,18 +1191,23 @@ static void htb_parent_to_leaf(struct htb_sched *q, struct htb_class *cl, parent->cmode = HTB_CAN_SEND; } +static void htb_class_free_rcu(struct rcu_head *head) +{ + kfree(container_of(head, struct htb_class, rcu)); +} + static void htb_destroy_class(struct Qdisc *sch, struct htb_class *cl) { if (!cl->level) { WARN_ON(!cl->un.leaf.q); qdisc_destroy(cl->un.leaf.q); } - gen_kill_estimator(&cl->bstats, &cl->rate_est); + gen_kill_estimator_rcu(&cl->bstats, &cl->rate_est); qdisc_put_rtab(cl->rate); qdisc_put_rtab(cl->ceil); tcf_destroy_chain(&cl->filter_list); - kfree(cl); + call_rcu(&cl->rcu, htb_class_free_rcu); } static void htb_destroy(struct Qdisc *sch) @@ -1573,6 +1579,7 @@ static int __init htb_module_init(void) static void __exit htb_module_exit(void) { unregister_qdisc(&htb_qdisc_ops); + rcu_barrier(); /* Wait for completion of call_rcu()'s */ } module_init(htb_module_init)