On Thu, Apr 15, 2021 at 12:42 AM Ferruh Yigit wrote: > > On 4/15/2021 3:55 AM, Suanming Mou wrote: > > Hi, > > > >> -----Original Message----- > >> From: Ferruh Yigit > >> Sent: Wednesday, April 14, 2021 9:07 PM > >> To: Suanming Mou ; Ori Kam ; > >> Andrew Rybchenko ; NBU-Contact-Thomas > >> Monjalon > >> Cc: dev@dpdk.org; Stephen Hemminger > >> 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 > >>>> Sent: Tuesday, March 16, 2021 3:27 AM > >>>> To: dev@dpdk.org > >>>> Cc: Stephen Hemminger ; Suanming Mou > >>>> > >>>> 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? We have some level of tests on this and so far current code looks safe. But we will try to increase the coverage and see how it goes. >