CODEWITHSUNDEEP
clinux-kernellinux-device-driver
srib
srib

Reputation: 168

What to prefer between `spin_lock_init` and `DEFINE_SPINLOCK` and when?

Is DEFINE_SPINLOCK preferable over spin_lock_init? What are the advantages of the former over the latter, and what are the possible drawbacks?

Upvotes: 5

Views: 5395

Answers (1)

Roland
Roland

Reputation: 6543

If you have a static data structure, DEFINE_SPINLOCK lets you declare a spinlock variable and initialize it in one line. However for anything allocated at runtime, for example when a spinlock is embedded in a bigger structure, then you need to allocate the memory and then call spin_lock_init().

I guess I would say that I prefer DEFINE_SPINLOCK when it is possible to use it. The advantage is tiny (compile-time initialization vs. runtime initialization, a couple lines less of code) but there's no real drawback. As I mentioned above, it's often not possible to use DEFINE_SPINLOCK, though.

Upvotes: 8

Related Questions