From: Jason Gunthorpe <jgg@ziepe.ca>
To: Gal Pressman <galpress@amazon.com>
Cc: Doug Ledford <dledford@redhat.com>,
linux-rdma@vger.kernel.org,
Alexander Matushevsky <matua@amazon.com>,
Firas JahJah <firasj@amazon.com>,
Yossi Leybovich <sleybo@amazon.com>
Subject: Re: [PATCH for-next 6/6] RDMA/efa: Do not delay freeing of DMA pages
Date: Wed, 15 Jan 2020 15:51:04 -0400 [thread overview]
Message-ID: <20200115195104.GA929@ziepe.ca> (raw)
In-Reply-To: <20200114085706.82229-7-galpress@amazon.com>
On Tue, Jan 14, 2020 at 10:57:06AM +0200, Gal Pressman wrote:
> When destroying a DMA mmapped object, there is no need to delay the
> pages freeing to dealloc_ucontext as the kernel itself will keep
> reference count for these pages.
Why does the commit message talk about dealloc_ucontext but doesn't
change dealloc_ucontext?
> + free_pages_exact(cq->cpu_addr, cq->size);
> rdma_user_mmap_entry_remove(cq->mmap_entry);
This is out of order, the pages can't be freed until the entry is
removed.
There is also a bug in rdma_user_mmap_entry_remove(),
entry->driver_removed needs to be set while holding the xa_lock or
this is not the required fence.
Jason
next prev parent reply other threads:[~2020-01-15 19:51 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-14 8:57 [PATCH for-next 0/6] EFA updates 2020-01-14 Gal Pressman
2020-01-14 8:57 ` [PATCH for-next 1/6] RDMA/efa: Unified getters/setters for device structs bitmask access Gal Pressman
2020-01-15 19:31 ` Jason Gunthorpe
2020-01-16 7:05 ` Gal Pressman
2020-01-14 8:57 ` [PATCH for-next 2/6] RDMA/efa: Properly document the interrupt mask register Gal Pressman
2020-01-14 8:57 ` [PATCH for-next 3/6] RDMA/efa: Device definitions documentation updates Gal Pressman
2020-01-14 8:57 ` [PATCH for-next 4/6] RDMA/efa: Remove {} brackets from single statement if Gal Pressman
2020-01-14 8:57 ` [PATCH for-next 5/6] RDMA/efa: Remove unused ucontext parameter from efa_qp_user_mmap_entries_remove Gal Pressman
2020-01-14 8:57 ` [PATCH for-next 6/6] RDMA/efa: Do not delay freeing of DMA pages Gal Pressman
2020-01-15 19:51 ` Jason Gunthorpe [this message]
2020-01-16 8:26 ` Gal Pressman
2020-01-15 19:58 ` [PATCH for-next 0/6] EFA updates 2020-01-14 Jason Gunthorpe
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