On Wed, 2007-05-16 at 14:13 -0700, Christoph Lameter wrote: > On Wed, 16 May 2007, Peter Zijlstra wrote: > > > How we know that we are out of trouble? Just try another alloc and see? > > > If > > > that is the case then we may be failing allocations after the memory > > > situation has cleared up. > > No, no, for each regular allocation we retry to populate ->cpu_slab with > > a new slab. If that works we're out of the woods and the ->reserve_slab > > is cleaned up. > > Hmmm.. so we could simplify the scheme by storing the last rank > somewheres.
Not sure how that would help.. > If the alloc has less priority and we can extend the slab then > clear up the situation. > > If we cannot extend the slab then the alloc must fail. That is exactly what is done; and as mpm remarked the other day, its a binary system; we don't need full gfp fairness just ALLOC_NO_WATERMARKS. And that is already found in ->reserve_slab; if present the last allocation needed it; if not the last allocation was good. > Could you put the rank into the page flags? On 64 bit at least there > should be enough space. Current I stick the newly allocated page's rank in page->rank (yet another overload of page->index). I've not yet seen the need to keep it around longer. - 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/
