On 12/19/12 11:42, Navdeep Parhar wrote: > 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.
er, I think I told you why tcp_usr_accept holds the pcbinfo lock, which wasn't your original question... :-) _______________________________________________ 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"
