From mboxrd@z Thu Jan 1 00:00:00 1970 From: laijs@cn.fujitsu.com (Lai Jiangshan) Date: Wed, 10 Oct 2012 15:52:08 +0800 Subject: [lttng-dev] [RFC] re-document rculfstack and even rename it Message-ID: <50752928.3050006@cn.fujitsu.com> rculfstack is not really require RCU-only. 1) cds_lfs_push_rcu() don't need any lock, don't need RCU nor other locks. 2) cds_lfs_pop_rcu() don't only one of the following synchronization(not only RCU): A) use rcu_read_lock() to protect cds_lfs_pop_rcu() and use synchronize_rcu() or call_rcu() to free the popped node. (current comments said we need this synchronization, and thus we named this struct with rcu prefix. But actually, the followings are OK, and are more popular/friendly) B) use mutexs/locks to protect cds_lfs_pop_rcu(), we can free to free/modify the popped node any time, we don't need any synchronization when free them. C) only ONE thread can call cds_lfs_pop_rcu(). (multi-providers-single customer) D) others, like read-write locks. I consider B) and C) are more popular. In linux kernel, kernel/task_work.c uses a hybird ways of B) and C). I suggest to rename it, Or document B) and C) at least. Thanks, Lai