Re: Deadlock on the mm->mmap_sem

Benjamin LaHaise
2001-09-19T21:14:15Z

On Wed, Sep 19, 2001 at 08:45:46PM +0200, Andrea Arcangeli wrote:
> To be pedantic the only idea I shared with the old code (but that's just
> the idea, not the implementation, so AFIK only a patent on such idea
> could protect it from its free usage usage) is to return the rwsem again
> from rwsem_wake and friends to avoid saving it in the asm slow path, and
> I written that:

Your patch moved a bunch of code into asm-i386/rwsem_xchgadd.h. That
code was derived from the spinlock code by me into the first rwsems,
then David reworked bits of it, as wel as you. But there is no
copyright on that file indicating this heritage. If you look at
how strict commercial copyright control can be, even copying a
single line of code mentally by retyping it can still mandate the
copyright legacy. I'm sure it's just an oversight, but it's
probably one we *all* need to be reminded of every now and again.

-ben