Re: [PATCH] [0/6] HUGETLB memory commitment

[Andrew Morton]

Andy Whitcroft <apw@xxxxxxxxxxxx> wrote:
>
> HUGETLB Overcommit Handling
> ---------------------------
> When building mappings the kernel tracks committed but not yet
> allocated pages against available memory and swap preventing memory
> allocation problems later.  The introduction of hugetlb pages has
> has significant ramifications for this accounting as the pages used
> to back them are already removed from the available memory pool.

Sorry, but I just don't see why we need all this complexity and generality.

If there was any likelihood that there would be additional memory domains
in the 2.6 future then OK.  But I don't think there will be.  We simply
need some little old patch which fixes this bug.

Such as adding a `vma' arg to vm_enough_memory() and vm_unacct_memory() and
doing

	if (is_vm_hugetlb_page(vma))
		return;

and

-	allowed = totalram_pages * sysctl_overcommit_ratio / 100;
+	allowed = (totalram_pages - htlbpagemem << HPAGE_SHIFT) *
+			sysctl_overcommit_ratio / 100;

in cap_vm_enough_memory().

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/