On Tue, Sep 01, 2015 at 09:00:57PM +0800, Herbert Xu wrote: > On Tue, Sep 01, 2015 at 02:46:48PM +0200, Phil Sutter wrote: > > > > This is not an inherent behaviour of the implementation but general > > agreement. The insertion may fail non-permanently (returning -EBUSY), > > users are expected to handle this by retrying the operation. > > Absolutely not. The only reason for an insertion to fail is if we > can't allocate enough memory. Unless the user is also looping its > kmalloc calls it definitely shouldn't be retrying the insert.
rhashtable_insert_fast() returns -EBUSY if the table is full (rht_grow_above_100() returns true) and an asynchronous rehash operation is active. AFAICT, this is not necessarily caused by memory pressure. > If an expansion fails it means either that the system is suffering > a catastrophic memory shortage, or the user of rhashtable is doing > something wrong. Hmm. Since memory allocation is first tried with GFP_ATOMIC set and upon failure retried in background, this seems like a situation which might happen during normal use. If that already indicates a severe problem, why retry in background at all? Cheers, Phil -- 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
