Conventions used
There are a number of text conventions used throughout this book.
Code in text: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "We can lock/unlock the spinlock using the spin_lock() and spin_unlock() inline functions, both defined in include/linux/spinlock.h."
A block of code is set as follows:
struct mutex {
atomic_long_t owner;
spinlock_t wait_lock;
#ifdef CONFIG_MUTEX_SPIN_ON_OWNER
struct optimistic_spin_queue osq; /* Spinner MCS lock */
When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:
struct fake_data {
struct i2c_client *client;
u16 reg_conf;
struct mutex mutex;
};
Any command-line input or output is written as follows:
[342081.385491] Wait queue example [342081.385505] Going to sleep my_init [342081.385515] Waitqueue module handler work_handler [342086.387017] Wake up the sleeping module
Tips or Important Notes
Appear like this.