On Mon, 29 Oct 2018 13:20:27 -0700 Florin Coras <fcoras.li...@gmail.com> wrote:
> Hi Stephen, > > No, we don’t support RCU. Wouldn’t rw-locks be enough to support your > usecases? > > Florin > > > On Oct 29, 2018, at 12:40 PM, Stephen Hemminger > > <step...@networkplumber.org> wrote: > > > > Is it possible to do Read Copy Update with VPP? Either using Userspace RCU > > (https://librcu.org) > > or manually. RCU is very efficient way to handle read mostly tables and > > other dynamic cases > > such as plugins. > > > > The several things that are needed are non-preempt, atomic update of a > > pointer and a mechanism to be sure > > all active threads have gone through a quiescent period. I don't think VPP > > will preempt one node > > for another so that is done. The atomic update is relatively > > easy with basic barriers, either from FD.IO, DPDK, or native compiler > > operations. But > > is there an API to have a quiescent period marker in the main VPP vector > > scheduler? > > > > Something like the QSBR model of Userspace RCU library. > > (each thread calls rcu_queiscent_state() periodically) > > would be ideal. > > > > -=-=-=-=-=-=-=-=-=-=-=- > > Links: You receive all messages sent to this group. > > > > View/Reply Online (#11023): https://lists.fd.io/g/vpp-dev/message/11023 > > Mute This Topic: https://lists.fd.io/mt/27785182/675152 > > Group Owner: vpp-dev+ow...@lists.fd.io > > Unsubscribe: https://lists.fd.io/g/vpp-dev/unsub [fcoras.li...@gmail.com] > > -=-=-=-=-=-=-=-=-=-=-=- > No reader-writer locks are 100's of times slower. In fact reader write locks are slower than normal spin lock.
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