> -----Original Message----- > From: Ferruh Yigit <ferruh.yi...@intel.com> > Sent: Thursday, April 15, 2021 3:43 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>; > Matan Azrad <ma...@nvidia.com>; Shahaf Shuler <shah...@nvidia.com>; Ajit > Khaparde <ajit.khapa...@broadcom.com>; Somnath Kotur > <somnath.ko...@broadcom.com> > Subject: Re: [dpdk-dev] [PATCH 1/2] ethdev: make flow API primary/secondary > process safe > > On 4/15/2021 3:55 AM, Suanming Mou 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. > > Correct > > > (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. > > > > I am also not quite sure how PMDs that doesn't require mutex at all, (mlx5, > bnxt, > sfc) behave on multi process. Is calling flow APIs from both primary/secondary > safe?
This depends on the vendor driver. For mlx, it should be safe, not sure others. > > >> > >> > >> Stephen, > >> Are you aware of any downside setting 'PTHREAD_PROCESS_SHARED' > >> attribute to the mutex? Any possible performance implications? > >> > >> Ori, > >> Since mlx is heavily using the flow API, is it possible to test this > >> patch? If there is no negative impact, I think we can get this patch, what > >> do > you think? > >> > >>>>
