> -----Original Message----- > From: Maxime Coquelin <mcoqu...@redhat.com> > Sent: Monday, June 7, 2021 9:20 PM > To: Hu, Jiayu <jiayu...@intel.com>; dev@dpdk.org > Cc: maxime.coque...@redhat.com; Xia, Chenbo <chenbo....@intel.com>; > Wang, Yinan <yinan.w...@intel.com> > Subject: Re: [PATCH 0/2] provide thread unsafe async registration functions > > Hi Jiayu, > > On 6/7/21 10:07 AM, Hu, Jiayu wrote: > > Hi Maxime, > > > >> -----Original Message----- > >> From: Maxime Coquelin <mcoqu...@redhat.com> > >> Sent: Friday, June 4, 2021 3:25 PM > >> To: Hu, Jiayu <jiayu...@intel.com>; dev@dpdk.org > >> Cc: maxime.coque...@redhat.com; Xia, Chenbo <chenbo....@intel.com>; > >> Wang, Yinan <yinan.w...@intel.com> > >> Subject: Re: [PATCH 0/2] provide thread unsafe async registration > functions > >> > >> Sorry, for previous blank reply. > >> > >> On 5/28/21 10:11 AM, Jiayu Hu wrote: > >>> Lock protection is needed during the vhost notifies the application of > >>> device readiness, so the first patch is to add lock protection. After > >>> performing locking, existed async vhost registration functions will cause > >>> deadlock, as they acquire lock too. So the second patch is to provide > >>> unsafe registration functions to support calling within vhost callback > >>> functions. > >> > >> I agree the callback should be always protected, and in that case having > >> a new thread-unsafe API makes sense for async registration. > >> > >> Regarding backport, I'm not sure what we should do. > >> > >> Backporting new API is a no-go, but with only backporting patch 1 async > >> feature will be always broken on 20.11 LTS, right? > > > > Yes, if only backporting this fix patch to 20.11 LTS, it may break apps who > call > > async registration functions inside vhost callbacks. > > > > How about making this patch not a fix, but a new feature? > > Async will be still broken in v20.11 in this case. > Maybe the better thing would be to remove async support in v20.11, as > its support was quite limited in that release anyway. Does that make > sense?
OK, that makes sense to me. Thanks, Jiayu > > Thanks, > Maxime > > > Thanks, > > Jiayu > >> > >> What do you think? > >> > >> Thanks, > >> Maxime > >> > >>> Jiayu Hu (2): > >>> vhost: fix lock on device readiness notification > >>> vhost: add thread unsafe async registration functions > >>> > >>> doc/guides/prog_guide/vhost_lib.rst | 12 +++ > >>> lib/vhost/rte_vhost_async.h | 42 ++++++++++ > >>> lib/vhost/version.map | 4 + > >>> lib/vhost/vhost.c | 161 > >>> +++++++++++++++++++++++++++-------- > - > >>> lib/vhost/vhost_user.c | 5 +- > >>> 5 files changed, 180 insertions(+), 44 deletions(-) > >>> > >
