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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/preempt.h
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'include/linux/preempt.h')
-rw-r--r--include/linux/preempt.h62
1 files changed, 62 insertions, 0 deletions
diff --git a/include/linux/preempt.h b/include/linux/preempt.h
new file mode 100644
index 000000000000..dd98c54a23b4
--- /dev/null
+++ b/include/linux/preempt.h
@@ -0,0 +1,62 @@
+#ifndef __LINUX_PREEMPT_H
+#define __LINUX_PREEMPT_H
+
+/*
+ * include/linux/preempt.h - macros for accessing and manipulating
+ * preempt_count (used for kernel preemption, interrupt count, etc.)
+ */
+
+#include <linux/config.h>
+#include <linux/linkage.h>
+
+#ifdef CONFIG_DEBUG_PREEMPT
+ extern void fastcall add_preempt_count(int val);
+ extern void fastcall sub_preempt_count(int val);
+#else
+# define add_preempt_count(val) do { preempt_count() += (val); } while (0)
+# define sub_preempt_count(val) do { preempt_count() -= (val); } while (0)
+#endif
+
+#define inc_preempt_count() add_preempt_count(1)
+#define dec_preempt_count() sub_preempt_count(1)
+
+#define preempt_count() (current_thread_info()->preempt_count)
+
+#ifdef CONFIG_PREEMPT
+
+asmlinkage void preempt_schedule(void);
+
+#define preempt_disable() \
+do { \
+ inc_preempt_count(); \
+ barrier(); \
+} while (0)
+
+#define preempt_enable_no_resched() \
+do { \
+ barrier(); \
+ dec_preempt_count(); \
+} while (0)
+
+#define preempt_check_resched() \
+do { \
+ if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) \
+ preempt_schedule(); \
+} while (0)
+
+#define preempt_enable() \
+do { \
+ preempt_enable_no_resched(); \
+ preempt_check_resched(); \
+} while (0)
+
+#else
+
+#define preempt_disable() do { } while (0)
+#define preempt_enable_no_resched() do { } while (0)
+#define preempt_enable() do { } while (0)
+#define preempt_check_resched() do { } while (0)
+
+#endif
+
+#endif /* __LINUX_PREEMPT_H */