linux-kernel - [PATCH tip/core/rcu 03/14] rcu: Avoid double multiply by HZ

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Sun, 11 Nov 2018 11:28:53 -0800
From:   "Paul E. McKenney" <paulmck@...ux.ibm.com>
To:     linux-kernel@...r.kernel.org
Cc:     mingo@...nel.org, jiangshanlai@...il.com, dipankar@...ibm.com,
        akpm@...ux-foundation.org, mathieu.desnoyers@...icios.com,
        josh@...htriplett.org, tglx@...utronix.de, peterz@...radead.org,
        rostedt@...dmis.org, dhowells@...hat.com, edumazet@...gle.com,
        fweisbec@...il.com, oleg@...hat.com, joel@...lfernandes.org,
        "Paul E. McKenney" <paulmck@...ux.ibm.com>
Subject: [PATCH tip/core/rcu 03/14] rcu: Avoid double multiply by HZ

The rcu_check_gp_start_stall() function multiplies the return value
from rcu_jiffies_till_stall_check() by HZ, but the units are already
in jiffies.  This commit therefore avoids the need for introduction of
a jiffies-squared unit by removing the extraneous multiplication.

Signed-off-by: Paul E. McKenney <paulmck@...ux.ibm.com>
---
 kernel/rcu/tree.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 121f833acd04..4933f5d9d992 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2603,7 +2603,7 @@ static void force_quiescent_state(void)
 static void
 rcu_check_gp_start_stall(struct rcu_node *rnp, struct rcu_data *rdp)
 {
-	const unsigned long gpssdelay = rcu_jiffies_till_stall_check() * HZ;
+	const unsigned long gpssdelay = rcu_jiffies_till_stall_check();
 	unsigned long flags;
 	unsigned long j;
 	struct rcu_node *rnp_root = rcu_get_root();
-- 
2.17.1