zone->wait_table_bits contains a wrong value

zone->wait_table_bits contains a wrong value

[Emanuel Hilgart]

I am not sure if this is a bug.

The return value of wait_table_bits(unsigned long size) is too large. 
hash_long(val,zone->wait_table_bits) exceeds the maximum array index of 
zone->wait_table.

mm/page_alloc.c
/*
 * This is an integer logarithm so that shifts can be used later
 * to extract the more random high bits from the multiplicative
 * hash function before the remainder is taken.
 */
static inline unsigned long wait_table_bits(unsigned long size)
{
        return ffz(~size);
}


assumption:  
   wait_table_size := 0x10

conclusion:
  wait_table_bits(0x10) = 5
  hash_long(val,5) = [ 0 ; 0x1f ]

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