Re: kernel BUGs when removing largish files with the SLOB allocator

From: Matt Mackall
Date: Tue Sep 12 2006 - 17:06:17 EST


On Tue, Sep 12, 2006 at 09:56:46PM +0100, David Howells wrote:
> Matt Mackall <mpm@xxxxxxxxxxx> wrote:
>
> > > > You just broke the bit that shrinks the arena.
> > >
> > > How? This is only called once when things are being initialised. There can
> > > be no SLOB objects allocated prior to that point.
> >
> > It's on a timer.
>
> So what then? The timer is still initialised:
>
> void kmem_cache_init(void)
> {
> +#if 0
> void *p = slob_alloc(PAGE_SIZE, 0, PAGE_SIZE-1);
>
> if (p)
> free_page((unsigned long)p);
> +#endif
>
> mod_timer(&slob_timer, jiffies + HZ);
> }

"allocate a page from the slob arena"
"if successful, release it to the page allocator"
"re-arm timer"

The only tricky part is the timer points back to _this very function_.

--
Mathematics is the supreme nostalgia of our time.
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