dev_lock() question

[Stanislav Sedov]

On Thu, Sep 29, 2005 at 06:55:38PM +0200, Divacky Roman wrote:
> Hi,
> 
> dev_lock() looks this way:
> 
> void
> dev_lock(void)
> {
> 	if (!mtx_initialized(&devmtx))
> 		mtx_init(&devmtx, "cdev", NULL, MTX_DEF);
> 	mtx_lock(&devmtx);
> }
> 
> I wonder why is the mtx_initialized checking necessary? shouldnt explicit
> initialization be sufficient?
> 
> thnx for answer
> 
> roman

Moving "mtx_initialized()" check into mtx_init will decrease speed of other
mutexes initialization. We must check if it's initialized here because of
it's not permiited to pass already initialized mutex to mtx_init().