Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 5 Sep 2023 21:12:38 -0700 | From | Ira Weiny <> | Subject | Re: [PATCH RFC v2 13/18] dax/bus: Factor out dev dax resize logic |
| |
Jonathan Cameron wrote: > On Mon, 28 Aug 2023 22:21:04 -0700 > Ira Weiny <ira.weiny@intel.com> wrote: > > > Dynamic Capacity regions must limit dev dax resources to those areas > > which have extents backing real memory. Four alternatives were > > considered to manage the intersection of region space and extents: > > > > 1) Create a single region resource child on region creation which > > reserves the entire region. Then as extents are added punch holes in > > this reservation. This requires new resource manipulation to punch > > the holes and still requires an additional iteration over the extent > > areas which may already have existing dev dax resources used. > > > > 2) Maintain an ordered xarray of extents which can be queried while > > processing the resize logic. The issue is that existing region->res > > children may artificially limit the allocation size sent to > > alloc_dev_dax_range(). IE the resource children can't be directly > > used in the resize logic to find where space in the region is. > > > > 3) Maintain a separate resource tree with extents. This option is the > > same as 2) but with a different data structure. Most ideally we have > > some unified representation of the resource tree. > > > > 4) Create region resource children for each extent. Manage the dax dev > > resize logic in the same way as before but use a region child > > (extent) resource as the parents to find space within each extent. > > > > Option 4 can leverage the existing resize algorithm to find space within > > the extents. > > > > In preparation for this change, factor out the dev_dax_resize logic. > > For static regions use dax_region->res as the parent to find space for > > the dax ranges. Future patches will use the same algorithm with > > individual extent resources as the parent. > > > > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > Hi Ira, > > Some trivial comments on comments, but in general this indeed seems to be doing what you > say and factoring out the static allocation part. > > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Thanks!
> > > > --- > > drivers/dax/bus.c | 128 +++++++++++++++++++++++++++++++++--------------------- > > 1 file changed, 79 insertions(+), 49 deletions(-) > > > > diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c > > index b76e49813a39..ea7ae82b4687 100644 > > --- a/drivers/dax/bus.c > > +++ b/drivers/dax/bus.c > > @@ -817,11 +817,10 @@ static int devm_register_dax_mapping(struct dev_dax *dev_dax, int range_id) > > return 0; > > } > > > > > -static ssize_t dev_dax_resize(struct dax_region *dax_region, > > - struct dev_dax *dev_dax, resource_size_t size) > > +/* > > /** > > Suitable builds will then check this doc matches the function etc > even if this is never included into any of the docs build.
Done.
> > > + * dev_dax_resize_static - Expand the device into the unused portion of the > > + * region. This may involve adjusting the end of an existing resource, or > > + * allocating a new resource. > > + * > > + * @parent: parent resource to allocate this range in. > > + * @dev_dax: DAX device we are creating this range for > > Trivial: Doesn't seem to be consistent on . or not
That is because my brain has a real consistency issue on this... ;-)
'.' removed.
Thanks again, Ira
| ![\](/images/icornerr.gif) |