On Thu, 15 Apr 2021 02:55:17 +0000 Suanming Mou <suanmi...@nvidia.com> wrote:
> Hi, > > > -----Original Message----- > > From: Ferruh Yigit <ferruh.yi...@intel.com> > > Sent: Wednesday, April 14, 2021 9:07 PM > > To: Suanming Mou <suanmi...@nvidia.com>; Ori Kam <or...@nvidia.com>; > > Andrew Rybchenko <andrew.rybche...@oktetlabs.ru>; NBU-Contact-Thomas > > Monjalon <tho...@monjalon.net> > > Cc: dev@dpdk.org; Stephen Hemminger <step...@networkplumber.org> > > Subject: Re: [dpdk-dev] [PATCH 1/2] ethdev: make flow API primary/secondary > > process safe > > > > On 3/16/2021 11:48 PM, Suanming Mou wrote: > > > Hi Stephen, > > > > > >> -----Original Message----- > > >> From: Stephen Hemminger <step...@networkplumber.org> > > >> Sent: Tuesday, March 16, 2021 3:27 AM > > >> To: dev@dpdk.org > > >> Cc: Stephen Hemminger <step...@networkplumber.org>; Suanming Mou > > >> <suanmi...@nvidia.com> > > >> Subject: [PATCH 1/2] ethdev: make flow API primary/secondary process > > >> safe > > >> > > >> Posix mutex are not by default safe for protecting for usage from > > >> multiple processes. The flow ops mutex could be used by both primary > > >> and secondary processes. > > > > > > Process safe is something more widely scope. I assume it should be > > > another > > feature but not a bugfix for thread-safe? > > > And the fag RTE_ETH_DEV_FLOW_OPS_THREAD_SAFE we have added is just > > thread safe. > > > > > > > Hi Suanming, > > > > I think 'RTE_ETH_DEV_FLOW_OPS_THREAD_SAFE' flag and what this patch > > address are different issues. > > > > 'RTE_ETH_DEV_FLOW_OPS_THREAD_SAFE' is to add/remove synchronization > > support for flow APIs, that is for thread safety as flag name suggests. > > > > This patch is to solve the problem for multi process, where commit log > > describes > > as posix mutex is not safe for multiple process. > > So for PMDs which not set the RTE_ETH_DEV_FLOW_OPS_THREAD_SAFE capability > bit, they will have the process level protection in multi-process. > For PMDs which set the RTE_ETH_DEV_FLOW_OPS_THREAD_SAFE capability bit, this > change does not help with these PMDs. If the PMD with > RTE_ETH_DEV_FLOW_OPS_THREAD_SAFE capability bit internally does not support > multi-process, they may still suffer crash etc. (If I understand correctly, > mlx PMD level now should support multi-process, but better to have the > confirmation from maintainers with much deeper level). > I assume this patch solves the posix mutex for multi-process only, hard to > say the flow API primary/secondary process safe after that patch. Maybe we need a FLOW_OPS_PROCESS_SAFE flag? and declare all existing drivers as not process safe?
