Commit 6e692ed3 authored Mar 25, 2006 by John Hawkes Committed by Linus Torvalds Mar 25, 2006

[PATCH] fix alloc_large_system_hash() roundup



The "rounded up to nearest power of 2 in size" algorithm in
alloc_large_system_hash is not correct.  As coded, it takes an otherwise
acceptable power-of-2 value and doubles it.  For example, we see the error
if we boot with thash_entries=2097152 which produces a hash table with
4194304 entries.

Signed-off-by: John Hawkes <hawkes@sgi.com>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent 962749af

mm/page_alloc.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -2702,8 +2702,7 @@ void __init alloc_large_system_hash(const char tablename,
		else
		numentries <<= (PAGE_SHIFT - scale);
		}
		/* rounded up to nearest power of 2 in size */
		numentries = 1UL << (long_log2(numentries) + 1);
		numentries = roundup_pow_of_two(numentries);

		/* limit allocation size to 1/16 total memory by default */
		if (max == 0) {

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