From: Bharata B Rao <bharata@linux.ibm.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>,
Jason Gunthorpe <jgg@mellanox.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linux-nvdimm@lists.01.org
Subject: Re: [PATCH 5/5] memremap: provide a not device managed memremap_pages
Date: Tue, 13 Aug 2019 10:26:11 +0530 [thread overview]
Message-ID: <20190813045611.GB16950@in.ibm.com> (raw)
In-Reply-To: <20190812150012.GA12700@lst.de>
On Mon, Aug 12, 2019 at 05:00:12PM +0200, Christoph Hellwig wrote:
> On Mon, Aug 12, 2019 at 08:20:58PM +0530, Bharata B Rao wrote:
> > On Sun, Aug 11, 2019 at 10:12:47AM +0200, Christoph Hellwig wrote:
> > > The kvmppc ultravisor code wants a device private memory pool that is
> > > system wide and not attached to a device. Instead of faking up one
> > > provide a low-level memremap_pages for it. Note that this function is
> > > not exported, and doesn't have a cleanup routine associated with it to
> > > discourage use from more driver like users.
> >
> > The kvmppc secure pages management code will be part of kvm-hv which
> > can be built as module too. So it would require memremap_pages() to be
> > exported.
> >
> > Additionally, non-dev version of the cleanup routine
> > devm_memremap_pages_release() or equivalent would also be requried.
> > With device being present, put_device() used to take care of this
> > cleanup.
>
> Oh well. We can add them fairly easily if we really need to, but I
> tried to avoid that. Can you try to see if this works non-modular
> for you for now until we hear more feedback from Dan?
Yes, this patchset works non-modular and with kvm-hv as module, it
works with devm_memremap_pages_release() and release_mem_region() in the
cleanup path. The cleanup path will be required in the non-modular
case too for proper recovery from failures.
Regards,
Bharata.
next prev parent reply other threads:[~2019-08-13 4:56 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-11 8:12 add a not device managed memremap_pages Christoph Hellwig
2019-08-11 8:12 ` [PATCH 1/5] resource: pass a name argument to devm_request_free_mem_region Christoph Hellwig
2019-08-11 8:12 ` [PATCH 2/5] resource: add a not device managed request_free_mem_region variant Christoph Hellwig
2019-08-11 22:52 ` Jason Gunthorpe
2019-08-12 7:40 ` Christoph Hellwig
2019-08-11 8:12 ` [PATCH 3/5] memremap: remove the dev field in struct dev_pagemap Christoph Hellwig
2019-08-11 8:12 ` [PATCH 4/5] memremap: don't use a separate devm action for devmap_managed_enable_get Christoph Hellwig
2019-08-11 8:12 ` [PATCH 5/5] memremap: provide a not device managed memremap_pages Christoph Hellwig
2019-08-11 22:56 ` Jason Gunthorpe
2019-08-12 7:40 ` Christoph Hellwig
2019-08-12 14:50 ` Bharata B Rao
2019-08-12 15:00 ` Christoph Hellwig
2019-08-13 4:56 ` Bharata B Rao [this message]
2019-08-14 6:11 ` Christoph Hellwig
2019-08-14 8:58 ` Bharata B Rao
2019-08-14 11:25 ` Christoph Hellwig
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