On Thu, Feb 15, 2018 at 09:49:00AM -0600, Christopher Lameter wrote: > On Thu, 15 Feb 2018, Matthew Wilcox wrote: > > What if ... on startup, slab allocated a MAX_ORDER page for itself. > > It would then satisfy its own page allocation requests from this giant > > page. If we start to run low on memory in the rest of the system, slab > > can be induced to return some of it via its shrinker. If slab runs low > > on memory, it tries to allocate another MAX_ORDER page for itself. > > The inducing of releasing memory back is not there but you can run SLUB > with MAX_ORDER allocations by passing "slab_min_order=9" or so on bootup. This is subtly different from the idea that I had. If you set slub_min_order to 9, then slub will allocate 2MB pages for each slab, so allocating one object from kmalloc-32 and one object from dentry will cause 4MB to be taken from the system. What I was proposing was an intermediate page allocator where slab would request 2MB for its own uses all at once, then allocate pages from that to individual slabs, so allocating a kmalloc-32 object and a dentry object would result in 510 pages of memory still being available for any slab that needed it. -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
