Re: [PATCH 15/22] Do not disable interrupts in free_page_mlock()

[KOSAKI Motohiro]

> > @@ -556,6 +555,7 @@ static void __free_pages_ok(struct page *page, unsigned int order)
> >  	unsigned long flags;
> >  	int i;
> >  	int bad = 0;
> > +	int clearMlocked = PageMlocked(page);
> >  
> >  	for (i = 0 ; i < (1 << order) ; ++i)
> >  		bad += free_pages_check(page + i);
> > @@ -571,6 +571,8 @@ static void __free_pages_ok(struct page *page, unsigned int order)
> >  	kernel_map_pages(page, 1 << order, 0);
> >  
> >  	local_irq_save(flags);
> > +	if (unlikely(clearMlocked))
> > +		free_page_mlock(page);
> 
> I wonder what the compiler does in the case
> CONFIG_HAVE_MLOCKED_PAGE_BIT=n.  If it is dumb, this patch would cause
> additional code generation.

if CONFIG_HAVE_MLOCKED_PAGE_BIT=n, PageMlocked() is {return 0;} then
gcc can remove following code, I think.
	if (0) 
		free_page_mlock(page)



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/