From a47f0ce05ae12ce9acad62896ff703175764104e Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Thu, 24 Aug 2006 03:54:22 -0700 Subject: [PATCH] [XFRM]: Kill excessive refcounting of xfrm_state objects. The refcounting done for timers and hash table insertions are just wasted cycles. We can eliminate all of this refcounting because: 1) The implicit refcount when the xfrm_state object is active will always be held while the object is in the hash tables. We never kfree() the xfrm_state until long after we've made sure that it has been unhashed. 2) Timers are even easier. Once we mark that x->km.state as anything other than XFRM_STATE_VALID (__xfrm_state_delete sets it to XFRM_STATE_DEAD), any timer that fires will do nothing and return without rearming the timer. Therefore we can defer the del_timer calls until when the object is about to be freed up during GC. We have to use del_timer_sync() and defer it to GC because we can't do a del_timer_sync() while holding x->lock which all callers of __xfrm_state_delete hold. This makes SA changes even more light-weight. Signed-off-by: David S. Miller --- net/xfrm/xfrm_state.c | 53 ++++++++++++--------------------------------------- 1 file changed, 12 insertions(+), 41 deletions(-) diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c index 9ff00b7d6ad..0bc6a4b1cea 100644 --- a/net/xfrm/xfrm_state.c +++ b/net/xfrm/xfrm_state.c @@ -266,10 +266,8 @@ void km_state_expired(struct xfrm_state *x, int hard, u32 pid); static void xfrm_state_gc_destroy(struct xfrm_state *x) { - if (del_timer(&x->timer)) - BUG(); - if (del_timer(&x->rtimer)) - BUG(); + del_timer_sync(&x->timer); + del_timer_sync(&x->rtimer); kfree(x->aalg); kfree(x->ealg); kfree(x->calg); @@ -361,9 +359,9 @@ static void xfrm_timer_handler(unsigned long data) if (warn) km_state_expired(x, 0, 0); resched: - if (next != LONG_MAX && - !mod_timer(&x->timer, jiffies + make_jiffies(next))) - xfrm_state_hold(x); + if (next != LONG_MAX) + mod_timer(&x->timer, jiffies + make_jiffies(next)); + goto out; expired: @@ -378,7 +376,6 @@ expired: out: spin_unlock(&x->lock); - xfrm_state_put(x); } static void xfrm_replay_timer_handler(unsigned long data); @@ -433,19 +430,11 @@ int __xfrm_state_delete(struct xfrm_state *x) x->km.state = XFRM_STATE_DEAD; spin_lock(&xfrm_state_lock); hlist_del(&x->bydst); - __xfrm_state_put(x); hlist_del(&x->bysrc); - __xfrm_state_put(x); - if (x->id.spi) { + if (x->id.spi) hlist_del(&x->byspi); - __xfrm_state_put(x); - } xfrm_state_num--; spin_unlock(&xfrm_state_lock); - if (del_timer(&x->timer)) - __xfrm_state_put(x); - if (del_timer(&x->rtimer)) - __xfrm_state_put(x); /* All xfrm_state objects are created by xfrm_state_alloc. * The xfrm_state_alloc call gives a reference, and that @@ -676,17 +665,13 @@ xfrm_state_find(xfrm_address_t *daddr, xfrm_address_t *saddr, if (km_query(x, tmpl, pol) == 0) { x->km.state = XFRM_STATE_ACQ; hlist_add_head(&x->bydst, xfrm_state_bydst+h); - xfrm_state_hold(x); h = xfrm_src_hash(saddr, family); hlist_add_head(&x->bysrc, xfrm_state_bysrc+h); - xfrm_state_hold(x); if (x->id.spi) { h = xfrm_spi_hash(&x->id.daddr, x->id.spi, x->id.proto, family); hlist_add_head(&x->byspi, xfrm_state_byspi+h); - xfrm_state_hold(x); } x->lft.hard_add_expires_seconds = XFRM_ACQ_EXPIRES; - xfrm_state_hold(x); x->timer.expires = jiffies + XFRM_ACQ_EXPIRES*HZ; add_timer(&x->timer); } else { @@ -713,26 +698,20 @@ static void __xfrm_state_insert(struct xfrm_state *x) h = xfrm_dst_hash(&x->id.daddr, x->props.reqid, x->props.family); hlist_add_head(&x->bydst, xfrm_state_bydst+h); - xfrm_state_hold(x); h = xfrm_src_hash(&x->props.saddr, x->props.family); hlist_add_head(&x->bysrc, xfrm_state_bysrc+h); - xfrm_state_hold(x); if (xfrm_id_proto_match(x->id.proto, IPSEC_PROTO_ANY)) { h = xfrm_spi_hash(&x->id.daddr, x->id.spi, x->id.proto, x->props.family); hlist_add_head(&x->byspi, xfrm_state_byspi+h); - xfrm_state_hold(x); } - if (!mod_timer(&x->timer, jiffies + HZ)) - xfrm_state_hold(x); - - if (x->replay_maxage && - !mod_timer(&x->rtimer, jiffies + x->replay_maxage)) - xfrm_state_hold(x); + mod_timer(&x->timer, jiffies + HZ); + if (x->replay_maxage) + mod_timer(&x->rtimer, jiffies + x->replay_maxage); wake_up(&km_waitq); @@ -844,10 +823,8 @@ static struct xfrm_state *__find_acq_core(unsigned short family, u8 mode, u32 re xfrm_state_hold(x); x->timer.expires = jiffies + XFRM_ACQ_EXPIRES*HZ; add_timer(&x->timer); - xfrm_state_hold(x); hlist_add_head(&x->bydst, xfrm_state_bydst+h); h = xfrm_src_hash(saddr, family); - xfrm_state_hold(x); hlist_add_head(&x->bysrc, xfrm_state_bysrc+h); wake_up(&km_waitq); } @@ -955,8 +932,7 @@ out: memcpy(&x1->lft, &x->lft, sizeof(x1->lft)); x1->km.dying = 0; - if (!mod_timer(&x1->timer, jiffies + HZ)) - xfrm_state_hold(x1); + mod_timer(&x1->timer, jiffies + HZ); if (x1->curlft.use_time) xfrm_state_check_expire(x1); @@ -981,8 +957,7 @@ int xfrm_state_check_expire(struct xfrm_state *x) if (x->curlft.bytes >= x->lft.hard_byte_limit || x->curlft.packets >= x->lft.hard_packet_limit) { x->km.state = XFRM_STATE_EXPIRED; - if (!mod_timer(&x->timer, jiffies)) - xfrm_state_hold(x); + mod_timer(&x->timer, jiffies); return -EINVAL; } @@ -1177,7 +1152,6 @@ xfrm_alloc_spi(struct xfrm_state *x, u32 minspi, u32 maxspi) spin_lock_bh(&xfrm_state_lock); h = xfrm_spi_hash(&x->id.daddr, x->id.spi, x->id.proto, x->props.family); hlist_add_head(&x->byspi, xfrm_state_byspi+h); - xfrm_state_hold(x); spin_unlock_bh(&xfrm_state_lock); wake_up(&km_waitq); } @@ -1264,10 +1238,8 @@ void xfrm_replay_notify(struct xfrm_state *x, int event) km_state_notify(x, &c); if (x->replay_maxage && - !mod_timer(&x->rtimer, jiffies + x->replay_maxage)) { - xfrm_state_hold(x); + !mod_timer(&x->rtimer, jiffies + x->replay_maxage)) x->xflags &= ~XFRM_TIME_DEFER; - } } EXPORT_SYMBOL(xfrm_replay_notify); @@ -1285,7 +1257,6 @@ static void xfrm_replay_timer_handler(unsigned long data) } spin_unlock(&x->lock); - xfrm_state_put(x); } int xfrm_replay_check(struct xfrm_state *x, u32 seq) -- 2.11.4.GIT