Re: [PATCH] mm->rss is modified without page_table_lock held

From: Rasmus Andersen (rasmus@jaquet.dk)
Date: Sat Dec 09 2000 - 07:43:27 EST


On Sat, Dec 09, 2000 at 11:25:09AM +0100, Roberto Fichera wrote:
[...]
> >+ spin_lock(&mm->page_table_lock);
> > mm->rss++;
> >+ spin_unlock(&mm->page_table_lock);
> >
>
> [...snip...]
>
> Why we couldn't use atomic_inc(&mm->rss) here and below, avoiding to wrap
> the inc with a spin_lock()/spin_unlock() ?
>

AFAIR, because for some architectures we can't rely on mm->rss fitting in
an atomic_t. See davem's (somewhat short) post in this thread. Otherwise
search the archives for the original thread treating this problem.

-- 
        Rasmus(rasmus@jaquet.dk)

Television is called a medium because it is neither rare nor well-done. -- Anonymous - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Fri Dec 15 2000 - 21:00:17 EST