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-rw-r--r--kernel/slow-work.c118
-rw-r--r--kernel/sysctl.c9
2 files changed, 125 insertions, 2 deletions
diff --git a/kernel/slow-work.c b/kernel/slow-work.c
index 454abb21c8b..3f65900aa3c 100644
--- a/kernel/slow-work.c
+++ b/kernel/slow-work.c
@@ -14,7 +14,6 @@
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <linux/wait.h>
-#include <asm/system.h>
#define SLOW_WORK_CULL_TIMEOUT (5 * HZ) /* cull threads 5s after running out of
* things to do */
@@ -24,6 +23,14 @@
static void slow_work_cull_timeout(unsigned long);
static void slow_work_oom_timeout(unsigned long);
+#ifdef CONFIG_SYSCTL
+static int slow_work_min_threads_sysctl(struct ctl_table *, int, struct file *,
+ void __user *, size_t *, loff_t *);
+
+static int slow_work_max_threads_sysctl(struct ctl_table *, int , struct file *,
+ void __user *, size_t *, loff_t *);
+#endif
+
/*
* The pool of threads has at least min threads in it as long as someone is
* using the facility, and may have as many as max.
@@ -34,6 +41,51 @@ static unsigned slow_work_min_threads = 2;
static unsigned slow_work_max_threads = 4;
static unsigned vslow_work_proportion = 50; /* % of threads that may process
* very slow work */
+
+#ifdef CONFIG_SYSCTL
+static const int slow_work_min_min_threads = 2;
+static int slow_work_max_max_threads = 255;
+static const int slow_work_min_vslow = 1;
+static const int slow_work_max_vslow = 99;
+
+ctl_table slow_work_sysctls[] = {
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "min-threads",
+ .data = &slow_work_min_threads,
+ .maxlen = sizeof(unsigned),
+ .mode = 0644,
+ .proc_handler = slow_work_min_threads_sysctl,
+ .extra1 = (void *) &slow_work_min_min_threads,
+ .extra2 = &slow_work_max_threads,
+ },
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "max-threads",
+ .data = &slow_work_max_threads,
+ .maxlen = sizeof(unsigned),
+ .mode = 0644,
+ .proc_handler = slow_work_max_threads_sysctl,
+ .extra1 = &slow_work_min_threads,
+ .extra2 = (void *) &slow_work_max_max_threads,
+ },
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "vslow-percentage",
+ .data = &vslow_work_proportion,
+ .maxlen = sizeof(unsigned),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec_minmax,
+ .extra1 = (void *) &slow_work_min_vslow,
+ .extra2 = (void *) &slow_work_max_vslow,
+ },
+ { .ctl_name = 0 }
+};
+#endif
+
+/*
+ * The active state of the thread pool
+ */
static atomic_t slow_work_thread_count;
static atomic_t vslow_work_executing_count;
@@ -427,6 +479,64 @@ static void slow_work_oom_timeout(unsigned long data)
slow_work_may_not_start_new_thread = false;
}
+#ifdef CONFIG_SYSCTL
+/*
+ * Handle adjustment of the minimum number of threads
+ */
+static int slow_work_min_threads_sysctl(struct ctl_table *table, int write,
+ struct file *filp, void __user *buffer,
+ size_t *lenp, loff_t *ppos)
+{
+ int ret = proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos);
+ int n;
+
+ if (ret == 0) {
+ mutex_lock(&slow_work_user_lock);
+ if (slow_work_user_count > 0) {
+ /* see if we need to start or stop threads */
+ n = atomic_read(&slow_work_thread_count) -
+ slow_work_min_threads;
+
+ if (n < 0 && !slow_work_may_not_start_new_thread)
+ slow_work_enqueue(&slow_work_new_thread);
+ else if (n > 0)
+ mod_timer(&slow_work_cull_timer,
+ jiffies + SLOW_WORK_CULL_TIMEOUT);
+ }
+ mutex_unlock(&slow_work_user_lock);
+ }
+
+ return ret;
+}
+
+/*
+ * Handle adjustment of the maximum number of threads
+ */
+static int slow_work_max_threads_sysctl(struct ctl_table *table, int write,
+ struct file *filp, void __user *buffer,
+ size_t *lenp, loff_t *ppos)
+{
+ int ret = proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos);
+ int n;
+
+ if (ret == 0) {
+ mutex_lock(&slow_work_user_lock);
+ if (slow_work_user_count > 0) {
+ /* see if we need to stop threads */
+ n = slow_work_max_threads -
+ atomic_read(&slow_work_thread_count);
+
+ if (n < 0)
+ mod_timer(&slow_work_cull_timer,
+ jiffies + SLOW_WORK_CULL_TIMEOUT);
+ }
+ mutex_unlock(&slow_work_user_lock);
+ }
+
+ return ret;
+}
+#endif /* CONFIG_SYSCTL */
+
/**
* slow_work_register_user - Register a user of the facility
*
@@ -516,8 +626,12 @@ static int __init init_slow_work(void)
{
unsigned nr_cpus = num_possible_cpus();
- if (nr_cpus > slow_work_max_threads)
+ if (slow_work_max_threads < nr_cpus)
slow_work_max_threads = nr_cpus;
+#ifdef CONFIG_SYSCTL
+ if (slow_work_max_max_threads < nr_cpus * 2)
+ slow_work_max_max_threads = nr_cpus * 2;
+#endif
return 0;
}
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 5ec4543dfc0..82350f8f04f 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -48,6 +48,7 @@
#include <linux/acpi.h>
#include <linux/reboot.h>
#include <linux/ftrace.h>
+#include <linux/slow-work.h>
#include <asm/uaccess.h>
#include <asm/processor.h>
@@ -897,6 +898,14 @@ static struct ctl_table kern_table[] = {
.proc_handler = &scan_unevictable_handler,
},
#endif
+#ifdef CONFIG_SLOW_WORK
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "slow-work",
+ .mode = 0555,
+ .child = slow_work_sysctls,
+ },
+#endif
/*
* NOTE: do not add new entries to this table unless you have read
* Documentation/sysctl/ctl_unnumbered.txt