On Mon, May 13, 2019 at 3:38 PM Mark Johnston <ma...@freebsd.org> wrote: > > On Mon, May 13, 2019 at 01:45:29PM +0000, Andrey V. Elsukov wrote: > > Author: ae > > Date: Mon May 13 13:45:28 2019 > > New Revision: 347526 > > URL: https://svnweb.freebsd.org/changeset/base/347526 > > > > Log: > > Rework locking in BPF code to remove rwlock from fast path. > > > > On high packets rate the contention on rwlock in bpf_*tap*() functions > > can lead to packets dropping. To avoid this, migrate this code to use > > epoch(9) KPI and ConcurrencyKit's lists. > > > > * all lists changed to use CK_LIST; > > * reference counting added to bpf_if and bpf_d; > > * now bpf_if references ifnet and releases this reference on destroy; > > * each bpf_d descriptor references bpf_if when it is attached; > > * new struct bpf_program_buffer introduced to keep BPF filter programs; > > * bpf_program_buffer, bpf_d and bpf_if structures are freed by > > epoch_call(); > > * bpf_freelist and ifnet_departure event are no longer needed, thus > > both are removed; > > > > Reviewed by: melifaro > > Sponsored by: Yandex LLC > > Differential Revision: https://reviews.freebsd.org/D20224 > > This seems to introduce a possible recursion on the bpf cdev mutex. Now > bpfwrite() holds the mutex over the if_output call, which may enter > bpf_mtap() via bridge_transmit(), and bpf_mtap() may attempt to > reacquire the mutex.
It does, the sys.netinet.fibs_test.arpresolve_checks_interface_fib case can trigger a panic: root@:/usr/tests/sys/netinet # kyua test fibs_test:arpresolve_checks_interface_fib fibs_test:arpresolve_checks_interface_fib -> panic: _mtx_lock_sleep: recursed on non-recursive mutex bpf @ /usr/src/sys/net/bpf.c:2325 _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"