idr: Use local lock instead of preempt enable/disable
We need to protect the per cpu variable and prevent migration.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/linux/idr.h b/include/linux/idr.h
index 013fd9b..f62be0a 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -95,10 +95,14 @@
* Each idr_preload() should be matched with an invocation of this
* function. See idr_preload() for details.
*/
+#ifdef CONFIG_PREEMPT_RT_FULL
+void idr_preload_end(void);
+#else
static inline void idr_preload_end(void)
{
preempt_enable();
}
+#endif
/**
* idr_find - return pointer for given id
diff --git a/lib/idr.c b/lib/idr.c
index 5335c43..d0681a3 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -30,6 +30,7 @@
#include <linux/idr.h>
#include <linux/spinlock.h>
#include <linux/percpu.h>
+#include <linux/locallock.h>
#define MAX_IDR_SHIFT (sizeof(int) * 8 - 1)
#define MAX_IDR_BIT (1U << MAX_IDR_SHIFT)
@@ -366,6 +367,35 @@
idr_mark_full(pa, id);
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+static DEFINE_LOCAL_IRQ_LOCK(idr_lock);
+
+static inline void idr_preload_lock(void)
+{
+ local_lock(idr_lock);
+}
+
+static inline void idr_preload_unlock(void)
+{
+ local_unlock(idr_lock);
+}
+
+void idr_preload_end(void)
+{
+ idr_preload_unlock();
+}
+EXPORT_SYMBOL(idr_preload_end);
+#else
+static inline void idr_preload_lock(void)
+{
+ preempt_disable();
+}
+
+static inline void idr_preload_unlock(void)
+{
+ preempt_enable();
+}
+#endif
/**
* idr_preload - preload for idr_alloc()
@@ -401,7 +431,7 @@
WARN_ON_ONCE(in_interrupt());
might_sleep_if(gfp_mask & __GFP_WAIT);
- preempt_disable();
+ idr_preload_lock();
/*
* idr_alloc() is likely to succeed w/o full idr_layer buffer and
@@ -413,9 +443,9 @@
while (__this_cpu_read(idr_preload_cnt) < MAX_IDR_FREE) {
struct idr_layer *new;
- preempt_enable();
+ idr_preload_unlock();
new = kmem_cache_zalloc(idr_layer_cache, gfp_mask);
- preempt_disable();
+ idr_preload_lock();
if (!new)
break;