A solution for more GFP_xx flags?

[Christoph Lameter <clameter@sgi.com>]

I wonder if we could pass a pointer to an allocation structure
to the allocators instead of an unsigned long?

Right now the problem is that we need _node allocators to specify nodes 
and the memory policies and cpusets are determined by the allocation 
context of a process. This makes the allocators difficult to handle.

We could define a structure

struct allocation_control {
	unsigned long flags;	/* Traditional flags */
	int node;
	struct cpuset_context *cpuset;
	struct mempol *mpol;
};

We could define struct constants called GFP_KERNEL and GFP_ATOMIC.
const struct allocation_control gfp_kernel {
	GFP_KERNEL, -1, NULL, NULL
}

And then do

alloc_pages(n, gfp_kernel)

?

This would also solve the problem of allocations that do not occur in a 
proper process context. F.e. slab allocations are on behalf of the slab 
allocator and not on behalf of a process. Thus the cpuset and the memory 
policies should not influence that allocation. In that case we could have 
a special allocation_control structure for that context.

It would also get rid off all the xxx_node allocator variations.


--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>