| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Mon, 21 Jan 2008 00:46:59 +0100
From: Jarek Poplawski <jarkao2@...il.com>
To: netdev@...r.kernel.org
Cc: Badalian Vyacheslav <slavon@...telecom.ru>,
Patrick McHardy <kaber@...sh.net>, jamal <hadi@...erus.ca>,
David Miller <davem@...emloft.net>
Subject: [PATCH 1/3][NET] gen_estimator: faster gen_kill_estimator
gen_kill_estimator() is called during qdisc_destroy() with BHs disabled,
and each time does searching for each list member. This can block soft
interrupts for quite a long time when many classes are used. This patch
changes this by storing a pointer to internal gen_estimator structures
with gnet_stats_rate_est structures used by clients of gen_estimator.
This method removes currently possibile registering in gen_estimator the
same structures more than once, but it isn't used after all. (There is
added a warning if gen_new_estimator() is called with structures being
used by gen_estimator already.)
Reported-by: Badalian Vyacheslav <slavon@...telecom.ru>
Signed-off-by: Jarek Poplawski <jarkao2@...il.com>
[needs more testing]
---
include/linux/gen_stats.h | 2 ++
net/core/gen_estimator.c | 36 +++++++++++++++++++++++++++++++++---
2 files changed, 35 insertions(+), 3 deletions(-)
diff -Nurp 2.6.24-rc8-mm1-/include/linux/gen_stats.h 2.6.24-rc8-mm1+/include/linux/gen_stats.h
--- 2.6.24-rc8-mm1-/include/linux/gen_stats.h 2007-10-09 22:31:38.000000000 +0200
+++ 2.6.24-rc8-mm1+/include/linux/gen_stats.h 2008-01-20 20:37:08.000000000 +0100
@@ -28,11 +28,13 @@ struct gnet_stats_basic
* struct gnet_stats_rate_est - rate estimator
* @bps: current byte rate
* @pps: current packet rate
+ * @gen_estimator: internal data
*/
struct gnet_stats_rate_est
{
__u32 bps;
__u32 pps;
+ unsigned long gen_estimator;
};
/**
diff -Nurp 2.6.24-rc8-mm1-/net/core/gen_estimator.c 2.6.24-rc8-mm1+/net/core/gen_estimator.c
--- 2.6.24-rc8-mm1-/net/core/gen_estimator.c 2008-01-19 17:54:45.000000000 +0100
+++ 2.6.24-rc8-mm1+/net/core/gen_estimator.c 2008-01-20 20:58:35.000000000 +0100
@@ -139,6 +139,9 @@ skip:
rcu_read_unlock();
}
+static void gen_kill_estimator_find(struct gnet_stats_basic *bstats,
+ struct gnet_stats_rate_est *rate_est);
+
/**
* gen_new_estimator - create a new rate estimator
* @bstats: basic statistics
@@ -171,6 +174,10 @@ int gen_new_estimator(struct gnet_stats_
if (parm->interval < -2 || parm->interval > 3)
return -EINVAL;
+ if (rate_est->gen_estimator)
+ /* not sure: not zeroed in alloc or reused */
+ gen_kill_estimator_find(bstats, rate_est);
+
est = kzalloc(sizeof(*est), GFP_KERNEL);
if (est == NULL)
return -ENOBUFS;
@@ -184,6 +191,7 @@ int gen_new_estimator(struct gnet_stats_
est->avbps = rate_est->bps<<5;
est->last_packets = bstats->packets;
est->avpps = rate_est->pps<<10;
+ rate_est->gen_estimator = (unsigned long)est;
if (!elist[idx].timer.function) {
INIT_LIST_HEAD(&elist[idx].list);
@@ -209,13 +217,30 @@ static void __gen_kill_estimator(struct
* @bstats: basic statistics
* @rate_est: rate estimator statistics
*
- * Removes the rate estimator specified by &bstats and &rate_est
- * and deletes the timer.
+ * Removes the rate estimator specified by &bstats and &rate_est.
*
* NOTE: Called under rtnl_mutex
*/
void gen_kill_estimator(struct gnet_stats_basic *bstats,
- struct gnet_stats_rate_est *rate_est)
+ struct gnet_stats_rate_est *rate_est)
+{
+ if (rate_est && rate_est->gen_estimator) {
+ struct gen_estimator *e;
+
+ e = (struct gen_estimator *)rate_est->gen_estimator;
+
+ rate_est->gen_estimator = 0;
+ write_lock_bh(&est_lock);
+ e->bstats = NULL;
+ write_unlock_bh(&est_lock);
+
+ list_del_rcu(&e->list);
+ call_rcu(&e->e_rcu, __gen_kill_estimator);
+ }
+}
+
+static void gen_kill_estimator_find(struct gnet_stats_basic *bstats,
+ struct gnet_stats_rate_est *rate_est)
{
int idx;
struct gen_estimator *e, *n;
@@ -236,6 +261,11 @@ void gen_kill_estimator(struct gnet_stat
list_del_rcu(&e->list);
call_rcu(&e->e_rcu, __gen_kill_estimator);
+
+ WARN_ON_ONCE(1); /* gen_new_estimator() repeated? */
+ rate_est->gen_estimator = 0;
+
+ return;
}
}
}
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists