Re: [PATCH] General purpose zeroed page slab

Denis Vlasenko
2004-10-14T19:08:49Z

On Thursday 14 October 2004 21:49, Dave Jones wrote:
> On Thu, Oct 14, 2004 at 06:36:37PM +0100, Matthew Wilcox wrote:
> > On Thu, Oct 14, 2004 at 01:30:21PM -0400, Brian Gerst wrote:
> > > This doesn't work as you expect it does. The constructor is only called
> > > when a new slab is created, for each new object on the slab. It is
> > > _not_ run again when an object is freed. So if a page is freed then
> > > immediately reallocated it will contain garbage.
> >
> > The user is responsible for zeroing the page before handing it back to
> > the slab allocator.

BTW, zeroing with non-temporal stores may be a huge win here.
It is 300% faster on Athlon.

> That sounds like an accident waiting to happen.
> How about a CONFIG_DEBUG option to check its zeroed on free ?
--
vda