Messages in this thread | | | Subject | Re: kmemleak for MIPS | From | Eric Dumazet <> | Date | Wed, 30 Mar 2011 14:22:00 +0200 |
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Le mercredi 30 mars 2011 à 14:24 +0300, Daniel Baluta a écrit : > We have: > > > UDP hash table entries: 128 (order: 0, 4096 bytes) > > CONFIG_BASE_SMALL=0 > > udp_table_init looks like: > > if (!CONFIG_BASE_SMALL) > table->hash = alloc_large_system_hash(name, .. &table->mask); > /* > * Make sure hash table has the minimum size > */ > > Since CONFIG_BASE_SMALL is 0, we are allocating the hash using > alloc_large_system > Then: > if (CONFIG_BASE_SMALL || table->mask < UDP_HTABLE_SIZE_MIN - 1) { > table->hash = kmalloc(); > > table->mask is 127, and UDP_HTABLE_SIZE_MIN is 256, so we are allocating again > table->hash without freeing already allocated memory. > > We could free table->hash, before allocating the memory with kmalloc. > I don't fully understand the condition table->mask < UDP_HTABLE_SIZE_MIN - 1. > > Eric?
There is nothing special. UDP algo needs a minimum hash table that alloc_large_system_hash() was not able to provide (???)
As you spotted, there is no free_large-system_hash(), so we 'leak' the small hash table.
If machine has not enough memory to provide such a small hash table, I suggest using CONFIG_BASE_SMALL, since :
#define UDP_HTABLE_SIZE_MIN (CONFIG_BASE_SMALL ? 128 : 256)
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