On Thu, Dec 17, 2015 at 04:46:00PM +0800, Xin Long wrote:

sorry for late test, but unfortunately, my case with rhashtalbe still
return EBUSY.
I added some debug code in rhashtable_insert_rehash(), and found:
*future_tbl is null*

fail:
        /* Do not fail the insert if someone else did a rehash. */
        if (likely(rcu_dereference_raw(tbl->future_tbl))) {
                printk("future_tbl is there\n");
                return 0;
        } else {
                printk("future_tbl is null\n");
        }

any idea why ?

That's presumably because you got a genuine double rehash.

Until you post your code we can't really help you.

Cheers,
-- 
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