- perfctr_{init,exit}() don't need to be global: mark them static
- add comment to vperfctr_alloc() as to why an entire page is
claimed and reserved (mmap())
- add printk_ratelimit() to __vperfctr_set_cpus_allowed()
- add task_lock() new usage comment to <linux/sched.h>
Signed-off-by: Mikael Pettersson <[email protected]>
--- linux-2.6.7-mm4/drivers/perfctr/init.c.~1~ 2004-06-30 01:14:20.000000000 +0200
+++ linux-2.6.7-mm4/drivers/perfctr/init.c 2004-06-30 12:14:53.000000000 +0200
@@ -66,7 +66,7 @@
return 0;
}
-int __init perfctr_init(void)
+static int __init perfctr_init(void)
{
int err;
@@ -85,7 +85,7 @@
return 0;
}
-void __exit perfctr_exit(void)
+static void __exit perfctr_exit(void)
{
vperfctr_exit();
perfctr_cpu_exit();
--- linux-2.6.7-mm4/drivers/perfctr/virtual.c.~1~ 2004-06-30 02:29:12.000000000 +0200
+++ linux-2.6.7-mm4/drivers/perfctr/virtual.c 2004-06-30 12:22:25.000000000 +0200
@@ -145,6 +145,8 @@
spin_unlock(&nrctrs_lock);
}
+/* Allocate a `struct vperfctr'. Claim and reserve
+ an entire page so that it can be mmap():ed. */
static struct vperfctr *vperfctr_alloc(void)
{
unsigned long page;
@@ -366,9 +368,10 @@
{
if (cpus_intersects(new_mask, perfctr_cpus_forbidden_mask)) {
atomic_set(&perfctr->bad_cpus_allowed, 1);
- printk(KERN_WARNING "perfctr: process %d (comm %s) issued unsafe"
- " set_cpus_allowed() on process %d (comm %s)\n",
- current->pid, current->comm, owner->pid, owner->comm);
+ if (printk_ratelimit())
+ printk(KERN_WARNING "perfctr: process %d (comm %s) issued unsafe"
+ " set_cpus_allowed() on process %d (comm %s)\n",
+ current->pid, current->comm, owner->pid, owner->comm);
} else
atomic_set(&perfctr->bad_cpus_allowed, 0);
}
--- linux-2.6.7-mm4/include/linux/sched.h.~1~ 2004-06-29 12:43:28.000000000 +0200
+++ linux-2.6.7-mm4/include/linux/sched.h 2004-06-30 12:32:59.000000000 +0200
@@ -946,6 +946,9 @@
* Protects ->fs, ->files, ->mm, ->ptrace, ->group_info and synchronises with
* wait4().
*
+ * Synchronises set_cpus_allowed(), unlink, and creat of ->thread.perfctr.
+ * [if CONFIG_PERFCTR_VIRTUAL]
+ *
* Nests both inside and outside of read_lock(&tasklist_lock).
* It must not be nested with write_lock_irq(&tasklist_lock),
* neither inside nor outside.