From: Herbert Xu <herb...@gondor.apana.org.au> Date: Fri, 15 May 2015 11:06:23 +0800
> On Thu, May 14, 2015 at 10:22:17PM -0400, David Miller wrote: >> >> In my opinion, up to at least 2 X max_size, it's safe to allow the >> insert. Assuming a well choosen hash function and a roughly even >> distribution. > > OK I can make it 2 x max_size/table size. The rest of my email after what you quoted was intended to get one to consider this issue generally. :-) We wouldn't fail these inserts in any other hash table in the kernel. Would we stop making new TCP sockets if the TCP ehash chains are 3 entries deep? 4? 5? The answer to all of those is of course no for any hash chain length of N whatsoever. This new rhashtable behavior would be the default, and I seriously doubt that's a behavior people who use a hash table, generally speaking, desire or want. Should there perhaps be hard protections for _extremely_ long hash chains? Sure, I'm willing to entertain that kind of idea. But I would do so at the very far end of the spectrum. To the point where the hash table is degenerating into a linked list. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
