| 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
| ||
|
Message-ID: <20110324174802.GA18886@tsunami.ccur.com>
Date: Thu, 24 Mar 2011 13:48:02 -0400
From: Joe Korty <joe.korty@...r.com>
To: paulmck@...ux.vnet.ibm.com
Cc: fweisbec@...il.com, peterz@...radead.org, laijs@...fujitsu.com,
mathieu.desnoyers@...icios.com, dhowells@...hat.com,
loic.minier@...aro.org, dhaval.giani@...il.com, tglx@...utronix.de,
josh@...htriplett.org, houston.jim@...cast.net,
andi@...stfloor.org, linux-kernel@...r.kernel.org
Subject: [PATCH 12/24] jrcu: tuneable priority
jrcu: make daemon priority a tuneable.
Signed-off-by: Joe Korty <joe.korty@...r.com>
Index: b/kernel/jrcu.c
===================================================================
--- a/kernel/jrcu.c
+++ b/kernel/jrcu.c
@@ -504,20 +504,42 @@ void __init rcu_scheduler_starting(void)
#include <linux/param.h>
#include <linux/kthread.h>
+static int rcu_priority;
+static struct task_struct *rcu_daemon;
+
+static int jrcu_set_priority(int priority)
+{
+ struct sched_param param;
+
+ if (priority == 0) {
+ set_user_nice(current, -19);
+ return 0;
+ }
+
+ if (priority < 0)
+ param.sched_priority = MAX_USER_RT_PRIO + priority;
+ else
+ param.sched_priority = priority;
+
+ sched_setscheduler_nocheck(current, SCHED_RR, ¶m);
+ return param.sched_priority;
+}
+
static int jrcud_func(void *arg)
{
- set_user_nice(current, -19);
current->flags |= PF_NOFREEZE;
-
- pr_info("JRCU: daemon started. Will operate at ~%d Hz.\n", RCU_HZ);
+ rcu_priority = jrcu_set_priority(CONFIG_JRCU_DAEMON_PRIO);
rcu_timer_stop();
+ pr_info("JRCU: daemon started. Will operate at ~%d Hz.\n", rcu_hz);
+
while (!kthread_should_stop()) {
usleep_range(rcu_hz_period_us, rcu_hz_period_us + rcu_hz_delta_us);
rcu_delimit_batches();
}
pr_info("JRCU: daemon exiting\n");
+ rcu_daemon = NULL;
rcu_timer_restart();
return 0;
}
@@ -531,6 +553,7 @@ static __init int jrcud_start(void)
pr_warn("JRCU: daemon not started\n");
return -ENODEV;
}
+ rcu_daemon = p;
return 0;
}
late_initcall(jrcud_start);
@@ -552,8 +575,13 @@ static int rcu_debugfs_show(struct seq_f
msecs = div_s64(sched_clock() - rcu_timestamp, NSEC_PER_MSEC);
raw_local_irq_enable();
- seq_printf(m, "%14u: hz\n",
- rcu_hz);
+ seq_printf(m, "%14u: hz\n", rcu_hz);
+#ifdef CONFIG_JRCU_DAEMON
+ if (rcu_daemon)
+ seq_printf(m, "%14u: daemon priority\n", rcu_priority);
+ else
+ seq_printf(m, "%14s: daemon priority\n", "none, no daemon");
+#endif
seq_printf(m, "%14u: #passes seen\n",
rcu_stats.npasses);
seq_printf(m, "%14u: #batches seen\n",
Index: b/init/Kconfig
===================================================================
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -434,6 +434,17 @@ config JRCU_DAEMON
Required. The context switch when leaving the daemon is needed
to get the CPU to reliably participate in end-of-batch processing.
+config JRCU_DAEMON_PRIO
+ int "JRCU Daemon priority"
+ depends on JRCU_DAEMON
+ default 0
+ help
+ The JRCU daemon priority. If 0 then the daemon runs SCHED_OTHER.
+ If >0 then the daemon runs SCHED_RR and its priority will be
+ the value selected. If <0 then SCHED_RR is again selected, but
+ now its priority will be the biased downwards from the maximum
+ possible Posix priority.
+
config JRCU_LAZY
bool "Should JRCU be lazy recognizing end-of-batch"
depends on JRCU
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists