From: Matthew Wilcox <mawilcox(a)microsoft.com&gt; There was no need to have a minimum size of 4MB for NV-DIMMs; it was just a sanity check. Keep a check that it's at least one page in size because we really can't add less than a page to the memory map. Promote the print statement from 'debug' level to 'warning', since there was no information for my colleague who stumbled over this problem while attempting to add a 2MB chunk of memory. Reported-by: Cheng-mean Liu <soccerl(a)microsoft.com&gt; Signed-off-by: Matthew Wilcox <mawilcox(a)microsoft.com&gt; --- drivers/nvdimm/namespace_devs.c | 6 +++--- include/uapi/linux/ndctl.h | 4 ---- 2 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c index 5f1c6756e57c..95169308078a 100644 --- a/drivers/nvdimm/namespace_devs.c +++ b/drivers/nvdimm/namespace_devs.c @@ -1689,9 +1689,9 @@ struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev) } size = nvdimm_namespace_capacity(ndns); - if (size < ND_MIN_NAMESPACE_SIZE) { - dev_dbg(&ndns->dev, "%pa, too small must be at least %#x\n", - &size, ND_MIN_NAMESPACE_SIZE); + if (size < PAGE_SIZE) {

You're right. It should return -ENODEV regardless, but the warning should be for non-zero too small namespaces.

On Jul 12, 2017, at 10:13 AM, Dan Williams <dan.j.williams(a)intel.com&gt; wrote: On Wed, Jul 12, 2017 at 8:04 AM, Matthew Wilcox <willy(a)infradead.org&gt; wrote: >> You're right. It should return -ENODEV regardless, but the warning >> should be for non-zero too small namespaces. > > OK, try this: > > ---- 8< ---- > > From: Matthew Wilcox <mawilcox(a)microsoft.com&gt; > Date: Mon, 10 Jul 2017 14:26:59 -0400 > Subject: [PATCH] nvdimm: Remove minimum size requirement > > There was no need to have a minimum size of 4MB for NV-DIMMs; it was > just a sanity check. Keep a check that it's at least one page in size > because we really can't add less than a page to the memory map. > > Promote the print statement from 'debug' level to 'warning', since there > was no information for my colleague who stumbled over this problem while > attempting to add a 2MB chunk of memory. There may be some zero-sized > devices on the list, and those are not warned about. > > Truncate the resource_size_t to an int and print it using %d rather > than printing it in hex as a pointer to an address. We know it's less > than PAGE_SIZE, so it'll fit in an int. > > Reported-by: Cheng-mean Liu <soccerl(a)microsoft.com&gt; > Signed-off-by: Matthew Wilcox <mawilcox(a)microsoft.com&gt; > --- > drivers/nvdimm/namespace_devs.c | 7 ++++--- > include/uapi/linux/ndctl.h | 4 ---- > 2 files changed, 4 insertions(+), 7 deletions(-) > > diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c > index 5f1c6756e57c..518c3507f67f 100644 > --- a/drivers/nvdimm/namespace_devs.c > +++ b/drivers/nvdimm/namespace_devs.c > @@ -1689,9 +1689,10 @@ struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev) > } > > size = nvdimm_namespace_capacity(ndns); > - if (size < ND_MIN_NAMESPACE_SIZE) { > - dev_dbg(&ndns->dev, "%pa, too small must be at least %#x\n", > - &size, ND_MIN_NAMESPACE_SIZE); > + if (size < PAGE_SIZE) { > + if (size) > + dev_warn(&ndns->dev, "%d too small must be at least %ld\n", > + (int)size, PAGE_SIZE); > return ERR_PTR(-ENODEV); > } > > diff --git a/include/uapi/linux/ndctl.h b/include/uapi/linux/ndctl.h > index 6d3c54264d8e..3ad1623bb585 100644 > --- a/include/uapi/linux/ndctl.h > +++ b/include/uapi/linux/ndctl.h > @@ -299,10 +299,6 @@ enum nd_driver_flags { > ND_DRIVER_DAX_PMEM = 1 << ND_DEVICE_DAX_PMEM, > }; > > -enum { > - ND_MIN_NAMESPACE_SIZE = 0x00400000, > -}; > - I ran this patch through the unit tests. We'll need to keep this definition around until we can kill it's usage in ndctl since it's part of the uapi. I also need to go fix up the dpa-alloc test to understand the new assumptions. _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm(a)lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm