Hi lads, > > Hi Matan, > > On Fri, Jan 19, 2018 at 01:35:10PM +0000, Matan Azrad wrote: > > Hi Konstantin > > > > From: Ananyev, Konstantin, Friday, January 19, 2018 3:09 PM > > > > -----Original Message----- > > > > From: Matan Azrad [mailto:ma...@mellanox.com] > > > > Sent: Friday, January 19, 2018 12:52 PM > > > > To: Ananyev, Konstantin <konstantin.anan...@intel.com>; Thomas > > > > Monjalon <tho...@monjalon.net>; Gaetan Rivet > > > <gaetan.ri...@6wind.com>; > > > > Wu, Jingjing <jingjing...@intel.com> > > > > Cc: dev@dpdk.org; Neil Horman <nhor...@tuxdriver.com>; Richardson, > > > > Bruce <bruce.richard...@intel.com> > > > > Subject: RE: [PATCH v3 7/7] app/testpmd: adjust ethdev port ownership > > > > > > > > Hi Konstantin > > > > > > > > From: Ananyev, Konstantin, Friday, January 19, 2018 2:38 PM > > > > > To: Matan Azrad <ma...@mellanox.com>; Thomas Monjalon > > > > > <tho...@monjalon.net>; Gaetan Rivet <gaetan.ri...@6wind.com>; > > > Wu, > > > > > Jingjing <jingjing...@intel.com> > > > > > Cc: dev@dpdk.org; Neil Horman <nhor...@tuxdriver.com>; Richardson, > > > > > Bruce <bruce.richard...@intel.com> > > > > > Subject: RE: [PATCH v3 7/7] app/testpmd: adjust ethdev port > > > > > ownership > > > > > > > > > > Hi Matan, > > > > > > > > > > > -----Original Message----- > > > > > > From: Matan Azrad [mailto:ma...@mellanox.com] > > > > > > Sent: Thursday, January 18, 2018 4:35 PM > > > > > > To: Thomas Monjalon <tho...@monjalon.net>; Gaetan Rivet > > > > > > <gaetan.ri...@6wind.com>; Wu, Jingjing <jingjing...@intel.com> > > > > > > Cc: dev@dpdk.org; Neil Horman <nhor...@tuxdriver.com>; > > > Richardson, > > > > > > Bruce <bruce.richard...@intel.com>; Ananyev, Konstantin > > > > > > <konstantin.anan...@intel.com> > > > > > > Subject: [PATCH v3 7/7] app/testpmd: adjust ethdev port ownership > > > > > > > > > > > > Testpmd should not use ethdev ports which are managed by other > > > > > > DPDK entities. > > > > > > > > > > > > Set Testpmd ownership to each port which is not used by other > > > > > > entity and prevent any usage of ethdev ports which are not owned by > > > Testpmd. > > > > > > > > > > > > Signed-off-by: Matan Azrad <ma...@mellanox.com> > > > > > > --- > > > > > > app/test-pmd/cmdline.c | 89 > > > > > > +++++++++++++++++++----------------- > > > ---- > > > > > ----- > > > > > > app/test-pmd/cmdline_flow.c | 2 +- > > > > > > app/test-pmd/config.c | 37 ++++++++++--------- > > > > > > app/test-pmd/parameters.c | 4 +- > > > > > > app/test-pmd/testpmd.c | 63 ++++++++++++++++++++------------ > > > > > > app/test-pmd/testpmd.h | 3 ++ > > > > > > 6 files changed, 103 insertions(+), 95 deletions(-) > > > > > > > > > > > > diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c index > > > > > > 31919ba..6199c64 100644 > > > > > > --- a/app/test-pmd/cmdline.c > > > > > > +++ b/app/test-pmd/cmdline.c > > > > > > @@ -1394,7 +1394,7 @@ struct cmd_config_speed_all { > > > > > > &link_speed) < 0) > > > > > > return; > > > > > > > > > > > > - RTE_ETH_FOREACH_DEV(pid) { > > > > > > + RTE_ETH_FOREACH_DEV_OWNED_BY(pid, my_owner.id) { > > > > > > > > > > Why do we need all these changes? > > > > > As I understand you changed definition of RTE_ETH_FOREACH_DEV(), so > > > > > no testpmd should work ok default (no_owner case). > > > > > Am I missing something here? > > > > > > > > Now, After Gaetan suggestion RTE_ETH_FOREACH_DEV(pid) will iterate > > > over all valid and ownerless ports. > > > > > > Yes. > > > > > > > Here Testpmd wants to iterate over its owned ports. > > > > > > Why? Why it can't just iterate over all valid and ownerless ports? > > > As I understand it would be enough to fix current problems and would allow > > > us to avoid any changes in testmpd (which I think is a good thing). > > > > Yes, I understand that this big change is very daunted, But I think the > > current a lot of bugs in testpmd(regarding port ownership) even more > daunted. > > > > Look, > > Testpmd initiates some of its internal databases depends on specific port > > iteration, > > In some time someone may take ownership of Testpmd ports and testpmd will > > continue to touch them.
But if someone will take the ownership (assign new owner_id) that port will not appear in RTE_ETH_FOREACH_DEV() any more. > > > > If I look back on the fail-safe, its sole purpose is to have seamless > hotplug with existing applications. > > Port ownership is a genericization of some functions introduced by the > fail-safe, that could structure DPDK further. It should allow > applications to have a seamless integration with subsystems using port > ownership. Without this, port ownership cannot be used. > > Testpmd should be fixed, but follow the most common design patterns of > DPDK applications. Going with port ownership seems like a paradigm > shift. > > > In addition > > Using the old iterator in some places in testpmd will cause a race for > > run-time new ports(can be created by failsafe or any hotplug code): > > - testpmd finds an ownerless port(just now created) by the old iterator and > > start traffic there, > > - failsafe takes ownership of this new port and start traffic there. > > Problem! Could you shed a bit more light here - it would be race condition between whom and whom? As I remember in testpmd all control ops are done within one thread (main lcore). The only way to attach/detach port with it - invoke testpmd CLI "attach/detach" port. Konstantin > > Testpmd does not handle detection of new port. If it did, testing > fail-safe with it would be wrong. > > At startup, RTE_ETH_FOREACH_DEV already fixed the issue of registering > DEFERRED ports. There are still remaining issues regarding this, but I > think they should be fixed. The architecture does not need to be > completely moved to port ownership. > > If anything, this should serve as a test for your API with common > applications. I think you'd prefer to know and debug with testpmd > instead of firing up VPP or something like that to determine what went > wrong with using the fail-safe. > > > > > In addition > > As a good example for well-done application (free from ownership bugs) I > > tried here to adjust Tespmd to the new rules and BTW to fix a > lot of bugs. > > Testpmd has too much cruft, it won't ever be a good example of a > well-done application. > > If you want to demonstrate ownership, I think you should start an > example application demonstrating race conditions and their mitigation. > > I think that would be interesting for many DPDK users. > > > > > > > So actually applications which are not aware to the port ownership still > > are exposed to races, but if there use the old iterator(with the new > change) the amount of races decreases. > > > > Thanks, Matan. > > > Konstantin > > > > > > > > > > > I added to Testpmd ability to take an ownership of ports as the new > > > > ownership and synchronization rules suggested, Since Tespmd is a DPDK > > > > entity which wants that no one will touch its owned ports, It must > > > > allocate > > > an unique ID, set owner for its ports (see in main function) and > > > recognizes > > > them by its owner ID. > > > > > > > > > Konstantin > > > > > > > Regards, > -- > Gaëtan Rivet > 6WIND
