__devexit_p

.remove = __devexit_p(s3c2410wdt_remove),

进入init.h，

/* Functions marked as __devexit may be discarded at kernel link time, dependingon config options. Newer versions of binutils detect references fromretained sections to discarded sections and flag an error. Pointers to__devexit functions must use __devexit_p(function_name), the wrapper willinsert either the function_name or NULL, depending on the config options.*/#if defined(MODULE) || defined(CONFIG_HOTPLUG)#define __devexit_p(x) x#else#define __devexit_p(x) NULL#endif

这个标记根据是否配置MODULE/CONFIG_HOTPLUG来决定括号里是x还是为空。