On Tue 26 Feb 2019 at 00:15, Cong Wang <xiyou.wangc...@gmail.com> wrote: > On Mon, Feb 25, 2019 at 7:45 AM Vlad Buslov <vla...@mellanox.com> wrote: >> >> Function tc_dump_chain() obtains and releases block->lock on each iteration >> of its inner loop that dumps all chains on block. Outputting chain template >> info is fast operation so locking/unlocking mutex multiple times is an >> overhead when lock is highly contested. Modify tc_dump_chain() to only >> obtain block->lock once and dump all chains without releasing it. >> >> Signed-off-by: Vlad Buslov <vla...@mellanox.com> >> Suggested-by: Cong Wang <xiyou.wangc...@gmail.com> > > Thanks for the followup! > > Isn't it similar for __tcf_get_next_proto() in tcf_chain_dump()? > And for tc_dump_tfilter()?
Not really. These two dump all tp filters and not just a template, which is O(n) on number of filters and can be slow because it calls hw offload API for each of them. Our typical use-case involves periodic filter dump (to update stats) while multiple concurrent user-space threads are updating filters, so it is important for them to be able to execute in parallel.
