On 12/19/12 11:31, Vijay Singh wrote: > As it is today, a socket upcall on a listener socket is made with the > V_tcbinfo lock held. [tcp_input -> syncache_socket -> sonewconn -> > sowakeup]. > > I feel that the use of the V_tcbinfo is not consistent in the syncache code. > > In syncache_add(), we drop the lock before doing the lookup: > > INP_WUNLOCK(inp); > INP_INFO_WUNLOCK(&V_tcbinfo); > [..snip..] > sc = syncache_lookup(inc, &sch); /* returns locked entry */ > > However, when going through syncache_expand() or syncache_chkrst() we > keep the V_tcbinfo lock. > > Since the syncache has its own lock, do we need to hold the V_tcbinfo > lock when calling syncache_socket()?
Holding the pcbinfo lock prevents races between syncache_socket() and accept(). See rwatson's comment just above tcp_usr_accept. I noted this too (the comment above tod->tod_offload_socket() in tcp_syncache.c) back when I updated the TOE code in the kernel. Regards, Navdeep _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
