Add sync-1.md to SUMMARY

SUMMARY.md

@@ -41,6 +41,8 @@
     * [Clockevents framework](Timers/timers-5.md)
     * [x86 related clock sources](Timers/timers-6.md)
     * [Time related system calls](Timers/timers-7.md)
+* [Synchronization primitives](SyncPrim/README.md)
+    * [Introduction to spinlocks](SyncPrim/sync-1.md)
 * [Memory management](mm/README.md)
     * [Memblock](mm/linux-mm-1.md)
     * [Fixmaps and ioremap](mm/linux-mm-2.md)

SyncPrim/README.md

@@ -0,0 +1,5 @@
+# Synchronization primitives in the Linux kernel.
+
+This chapter describes synchronization primitivies in the Linux kernel.
+
+* [Introduction to spinloks](http://0xax.gitbooks.io/linux-insides/content/SyncPrim/sync-1.html) - the first part of this chapter describes implementation of spinlock mechanism in the Linux kernel.