From: Christoph Lameter <[EMAIL PROTECTED]> Date: Thu, 28 Jun 2007 21:22:22 -0700 (PDT)
> On Thu, 28 Jun 2007, David Miller wrote: > > > > Still a better solution would be to not use the slab allocator at all for > > > the objects that are used to send commands to the devices. These are not > > > permanent and grabbing a page from the pcp lists and putting it back is > > > likely as fast as performing a kmalloc. > > > > Jens Axboe wants to get references to the page structs behind > > kmalloc() allocated pages in his networking splice work. > > You can get such a reference and then the slab page will be in limbo if > all objects are freed until that reference is given up. The reference > method is also use by kmem_cache_vacate() (but that is slab internal). What about if someone kfree()'s that object meanwhile? Can we bump the SLAB object count just like we can a page? That's basically what's happening in the stuff Jens is working on, he needs to grab a reference to a SLAB object just like one can a page. Even if there is an intervening kfree (like a put_page()) the SLAB object is still live until all the references are put, and thus it can't get reallocated and given to another client by SLAB. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
