From: Michal Kalderon <mkalderon@marvell.com>
To: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Gal Pressman <galpress@amazon.com>,
Ariel Elior <aelior@marvell.com>,
"dledford@redhat.com" <dledford@redhat.com>,
"bmt@zurich.ibm.com" <bmt@zurich.ibm.com>,
"sleybo@amazon.com" <sleybo@amazon.com>,
"leon@kernel.org" <leon@kernel.org>,
"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>
Subject: RE: [EXT] Re: [PATCH v11 rdma-next 5/7] RDMA/qedr: Use the common mmap API
Date: Tue, 24 Sep 2019 08:25:34 +0000 [thread overview]
Message-ID: <MN2PR18MB3182A3C331E573CBB6A00380A1840@MN2PR18MB3182.namprd18.prod.outlook.com> (raw)
In-Reply-To: <20190923132933.GC12047@ziepe.ca>
> From: Jason Gunthorpe <jgg@ziepe.ca>
> Sent: Monday, September 23, 2019 4:30 PM
>
> External Email
>
> ----------------------------------------------------------------------
> On Mon, Sep 23, 2019 at 09:21:37AM +0000, Michal Kalderon wrote:
> > > From: linux-rdma-owner@vger.kernel.org <linux-rdma-
> > > owner@vger.kernel.org> On Behalf Of Gal Pressman
> > >
> > > On 19/09/2019 20:55, Jason Gunthorpe wrote:
> > > > Huh. If you recall we did all this work with the XA and the free
> > > > callback because you said qedr was mmaping BAR pages that had some
> > > > HW lifetime associated with them, and the HW resource was not to
> > > > be reallocated until all users were gone.
> > > >
> > > > I think it would be a better example of this API if you pulled the
> > > >
> > > > dev->ops->rdma_remove_user(dev->rdma_ctx, ctx->dpi);
> > > >
> > > > Into qedr_mmap_free().
> > > >
> > > > Then the rdma_user_mmap_entry_remove() will call it naturally as
> > > > it does entry_put() and if we are destroying the ucontext we
> > > > already know the mmaps are destroyed.
> > > >
> > > > Maybe the same basic comment for EFA, not sure. Gal?
> > >
> > > That's what EFA already does in this series, no?
> > > We no longer remove entries on dealloc_ucontext, only when the entry
> > > is freed.
> >
> > Actually, I think most of the discussions you had on the topic were
> > with Gal, but Some apply to qedr as well, however, for qedr, the only
> > hw resource we allocate (bar) is on alloc_ucontext , therefore we were
> > safe to free it on dealloc_ucontext as all mappings were already
> > zapped. Making the mmap_free a bit redundant for qedr except for the
> need to free the entry.
>
> I think if we are changing things to use this new interface then you should
> consistenly code so that the lifetime of the object in the mmap_entry is
> entirely controlled by the mmap_entry and not also split to the ucontext.
>
> Having mmapable object lifetimes linked to the ucontext is a bit of a hack
> really
>
Ok, but the ucontext "hack" will need to remain for other drivers.
> Jason
next prev parent reply other threads:[~2019-09-24 8:25 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-05 10:01 [PATCH v11 rdma-next 0/7] RDMA/qedr: Use the doorbell overflow recovery mechanism for RDMA Michal Kalderon
2019-09-05 10:01 ` [PATCH v11 rdma-next 1/7] RDMA/core: Move core content from ib_uverbs to ib_core Michal Kalderon
2019-09-05 10:01 ` [PATCH v11 rdma-next 2/7] RDMA/core: Create mmap database and cookie helper functions Michal Kalderon
2019-09-19 17:14 ` Jason Gunthorpe
2019-09-19 17:48 ` Jason Gunthorpe
2019-09-19 18:07 ` Jason Gunthorpe
2019-09-23 9:36 ` [EXT] " Michal Kalderon
2019-09-23 13:30 ` Jason Gunthorpe
2019-09-24 8:31 ` Michal Kalderon
2019-09-24 12:37 ` Jason Gunthorpe
2019-09-05 10:01 ` [PATCH v11 rdma-next 3/7] RDMA/efa: Use the common mmap_xa helpers Michal Kalderon
2019-09-19 17:37 ` Jason Gunthorpe
2019-09-23 9:15 ` Michal Kalderon
2019-09-23 13:28 ` Jason Gunthorpe
2019-09-05 10:01 ` [PATCH v11 rdma-next 4/7] RDMA/siw: " Michal Kalderon
2019-09-05 10:01 ` [PATCH v11 rdma-next 5/7] RDMA/qedr: Use the common mmap API Michal Kalderon
2019-09-19 17:55 ` Jason Gunthorpe
2019-09-20 13:39 ` Gal Pressman
2019-09-23 9:21 ` Michal Kalderon
2019-09-23 13:29 ` Jason Gunthorpe
2019-09-24 8:25 ` Michal Kalderon [this message]
2019-09-24 8:49 ` Pressman, Gal
2019-09-24 9:31 ` Michal Kalderon
2019-10-20 7:19 ` Gal Pressman
2019-10-21 17:33 ` Jason Gunthorpe
2019-10-23 6:40 ` Gal Pressman
2019-10-23 14:41 ` Jason Gunthorpe
2019-10-24 8:06 ` Gal Pressman
2019-09-05 10:01 ` [PATCH v11 rdma-next 6/7] RDMA/qedr: Add doorbell overflow recovery support Michal Kalderon
2019-09-19 18:02 ` Jason Gunthorpe
2019-09-20 13:30 ` Gal Pressman
2019-09-20 13:38 ` Jason Gunthorpe
2019-09-20 14:00 ` Gal Pressman
2019-09-23 9:37 ` Michal Kalderon
2019-09-25 19:16 ` [EXT] " Michal Kalderon
2019-09-25 19:21 ` Jason Gunthorpe
2019-09-25 19:37 ` Michal Kalderon
2019-09-26 19:10 ` Jason Gunthorpe
2019-09-23 9:30 ` Michal Kalderon
2019-09-23 13:26 ` Jason Gunthorpe
2019-09-05 10:01 ` [PATCH v11 rdma-next 7/7] RDMA/qedr: Add iWARP doorbell " Michal Kalderon
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