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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/include/linux/percpu_ida.h
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/include/linux/percpu_ida.h')
-rw-r--r--kernel/include/linux/percpu_ida.h82
1 files changed, 82 insertions, 0 deletions
diff --git a/kernel/include/linux/percpu_ida.h b/kernel/include/linux/percpu_ida.h
new file mode 100644
index 000000000..f5cfdd6a5
--- /dev/null
+++ b/kernel/include/linux/percpu_ida.h
@@ -0,0 +1,82 @@
+#ifndef __PERCPU_IDA_H__
+#define __PERCPU_IDA_H__
+
+#include <linux/types.h>
+#include <linux/bitops.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/spinlock_types.h>
+#include <linux/wait.h>
+#include <linux/cpumask.h>
+
+struct percpu_ida_cpu;
+
+struct percpu_ida {
+ /*
+ * number of tags available to be allocated, as passed to
+ * percpu_ida_init()
+ */
+ unsigned nr_tags;
+ unsigned percpu_max_size;
+ unsigned percpu_batch_size;
+
+ struct percpu_ida_cpu __percpu *tag_cpu;
+
+ /*
+ * Bitmap of cpus that (may) have tags on their percpu freelists:
+ * steal_tags() uses this to decide when to steal tags, and which cpus
+ * to try stealing from.
+ *
+ * It's ok for a freelist to be empty when its bit is set - steal_tags()
+ * will just keep looking - but the bitmap _must_ be set whenever a
+ * percpu freelist does have tags.
+ */
+ cpumask_t cpus_have_tags;
+
+ struct {
+ spinlock_t lock;
+ /*
+ * When we go to steal tags from another cpu (see steal_tags()),
+ * we want to pick a cpu at random. Cycling through them every
+ * time we steal is a bit easier and more or less equivalent:
+ */
+ unsigned cpu_last_stolen;
+
+ /* For sleeping on allocation failure */
+ wait_queue_head_t wait;
+
+ /*
+ * Global freelist - it's a stack where nr_free points to the
+ * top
+ */
+ unsigned nr_free;
+ unsigned *freelist;
+ } ____cacheline_aligned_in_smp;
+};
+
+/*
+ * Number of tags we move between the percpu freelist and the global freelist at
+ * a time
+ */
+#define IDA_DEFAULT_PCPU_BATCH_MOVE 32U
+/* Max size of percpu freelist, */
+#define IDA_DEFAULT_PCPU_SIZE ((IDA_DEFAULT_PCPU_BATCH_MOVE * 3) / 2)
+
+int percpu_ida_alloc(struct percpu_ida *pool, int state);
+void percpu_ida_free(struct percpu_ida *pool, unsigned tag);
+
+void percpu_ida_destroy(struct percpu_ida *pool);
+int __percpu_ida_init(struct percpu_ida *pool, unsigned long nr_tags,
+ unsigned long max_size, unsigned long batch_size);
+static inline int percpu_ida_init(struct percpu_ida *pool, unsigned long nr_tags)
+{
+ return __percpu_ida_init(pool, nr_tags, IDA_DEFAULT_PCPU_SIZE,
+ IDA_DEFAULT_PCPU_BATCH_MOVE);
+}
+
+typedef int (*percpu_ida_cb)(unsigned, void *);
+int percpu_ida_for_each_free(struct percpu_ida *pool, percpu_ida_cb fn,
+ void *data);
+
+unsigned percpu_ida_free_tags(struct percpu_ida *pool, int cpu);
+#endif /* __PERCPU_IDA_H__ */