On Tue, Sep 24, 2024 at 10:48:07PM -0400, Kent Overstreet wrote: > > I've been noticing rhashtable resize is surprisingly heavy (the default > parameters don't ever shrink the table, which is why it's not seen as > much). Most rhashtable users enable automatic shrinking. > And, when I was torture testing that code I tripped over what appeared > to be an infinite loop in rht_bucket() when a rehsah is in progress, > which I worked around in > > a592cdf5164d bcachefs: don't use rht_bucket() in btree_key_cache_scan() You must not walk the rhashtable internal data structures by hand. If you need to iterate through the whole table, use the provided walking mechanism. However, as rhashtable is dynamic, walking it during a resize may cause you to see some elements twice. If you want to avoid that, set up your own linked list of all elements for a completely stable walk. Cheers, -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
