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From: Dan Williams <dan.j.williams@intel.com>
To: Joao Martins <joao.m.martins@oracle.com>
Cc: Linux MM <linux-mm@kvack.org>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	 Christoph Hellwig <hch@lst.de>,
	linux-nvdimm <linux-nvdimm@lists.01.org>,
	 Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 11/12] device-dax: Add dis-contiguous resource support
Date: Wed, 25 Mar 2020 10:48:58 -0700	[thread overview]
Message-ID: <CAPcyv4gBQOh9sba+Zbpo6yw3sh9JCKC7Cd10qdNc7d1TvTFfYQ@mail.gmail.com> (raw)
In-Reply-To: <c673cba2-8749-d63e-f0b2-592ed753481d@oracle.com>

On Wed, Mar 25, 2020 at 3:35 AM Joao Martins <joao.m.martins@oracle.com> wrote:
>
> On 3/24/20 4:12 PM, Joao Martins wrote:
> > On 3/23/20 11:55 PM, Dan Williams wrote:
> >>  static ssize_t dev_dax_resize(struct dax_region *dax_region,
> >>              struct dev_dax *dev_dax, resource_size_t size)
> >>  {
> >>      resource_size_t avail = dax_region_avail_size(dax_region), to_alloc;
> >> -    resource_size_t dev_size = range_len(&dev_dax->range);
> >> +    resource_size_t dev_size = dev_dax_size(dev_dax);
> >>      struct resource *region_res = &dax_region->res;
> >>      struct device *dev = &dev_dax->dev;
> >> -    const char *name = dev_name(dev);
> >>      struct resource *res, *first;
> >> +    resource_size_t alloc = 0;
> >> +    int rc;
> >>
> >>      if (dev->driver)
> >>              return -EBUSY;
> >> @@ -684,38 +766,47 @@ static ssize_t dev_dax_resize(struct dax_region *dax_region,
> >>       * allocating a new resource.
> >>       */
> >>      first = region_res->child;
> >> -    if (!first)
> >> -            return __alloc_dev_dax_range(dev_dax, dax_region->res.start,
> >> -                            to_alloc);
> >
> > You probably want to retain the condition above?
> >
> > Otherwise it removes the ability to create new devices or resizing it , once we
> > have zero-ed the last one.
> >
>
> A quick unit test that I had stashed here to help explain what I mean:
>
>         cd /sys/bus/dax/devices
>         # dax0.0 is the only dax device in the corresponding dax_region
>         echo dax0.0 > dax0.0/driver/unbind
>         echo 0 > dax0.0/size
>         # Shouldn't fail but returns -ENOSPC despite having
>         # the full region available
>         cat $(readlink -f dax0.0/../dax_region/available_size) > dax0.0/size

Thanks! Will incorporate that test before resending the series.


  reply	other threads:[~2020-03-25 17:49 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-23 23:54 [PATCH 00/12] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
2020-03-23 23:54 ` [PATCH 01/12] device-dax: Drop the dax_region.pfn_flags attribute Dan Williams
2020-03-23 23:54 ` [PATCH 02/12] device-dax: Move instance creation parameters to 'struct dev_dax_data' Dan Williams
2020-03-23 23:54 ` [PATCH 03/12] device-dax: Make pgmap optional for instance creation Dan Williams
2020-03-23 23:54 ` [PATCH 04/12] device-dax: Kill dax_kmem_res Dan Williams
2020-03-23 23:55 ` [PATCH 05/12] device-dax: Add an allocation interface for device-dax instances Dan Williams
2020-03-23 23:55 ` [PATCH 06/12] device-dax: Introduce seed devices Dan Williams
2020-03-23 23:55 ` [PATCH 07/12] drivers/base: Make device_find_child_by_name() compatible with sysfs inputs Dan Williams
2020-03-23 23:55 ` [PATCH 08/12] device-dax: Add resize support Dan Williams
2020-03-23 23:55 ` [PATCH 09/12] mm/memremap_pages: Convert to 'struct range' Dan Williams
2020-03-23 23:55 ` [PATCH 10/12] mm/memremap_pages: Support multiple ranges per invocation Dan Williams
2020-03-23 23:55 ` [PATCH 11/12] device-dax: Add dis-contiguous resource support Dan Williams
2020-03-24 16:12   ` Joao Martins
2020-03-25 10:35     ` Joao Martins
2020-03-25 17:48       ` Dan Williams [this message]
2020-03-26 17:49         ` Joao Martins
2020-07-11  0:44     ` Dan Williams
2020-04-06 10:43   ` Joao Martins
2020-04-06 20:22     ` Dan Williams
2020-07-11  0:47       ` Dan Williams
2020-05-12 14:36   ` Joao Martins
2020-07-11  0:52     ` Dan Williams
2020-03-23 23:55 ` [PATCH 12/12] device-dax: Introduce 'mapping' devices Dan Williams
2020-03-24 16:27   ` Joao Martins
2020-03-24 23:51     ` Dan Williams

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