From: Joao Martins <joao.m.martins@oracle.com> To: Dan Williams <dan.j.williams@intel.com> Cc: linux-mm@kvack.org, dave.hansen@linux.intel.com, hch@lst.de, linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 11/12] device-dax: Add dis-contiguous resource support Date: Tue, 24 Mar 2020 16:12:21 +0000 [thread overview] Message-ID: <9a6ff83f-095c-0689-d6d1-693a6e9c07e6@oracle.com> (raw) In-Reply-To: <158500773552.2088294.8756587190550753100.stgit@dwillia2-desk3.amr.corp.intel.com> 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. > - for (res = first; to_alloc && res; res = res->sibling) { > +retry: > + rc = -ENOSPC; > + for (res = first; res; res = res->sibling) { > struct resource *next = res->sibling; > - resource_size_t free; > > /* space at the beginning of the region */ > - free = 0; > - if (res == first && res->start > dax_region->res.start) > - free = res->start - dax_region->res.start; > - if (free >= to_alloc && dev_size == 0) > - return __alloc_dev_dax_range(dev_dax, > - dax_region->res.start, to_alloc); > - > - free = 0; > + if (res == first && res->start > dax_region->res.start) { > + alloc = min(res->start - dax_region->res.start, > + to_alloc); > + rc = __alloc_dev_dax_range(dev_dax, > + dax_region->res.start, alloc); > + break; > + } > + > + alloc = 0; > /* space between allocations */ > if (next && next->start > res->end + 1) > - free = next->start - res->end + 1; > + alloc = min(next->start - (res->end + 1), to_alloc); > > /* space at the end of the region */ > - if (free < to_alloc && !next && res->end < region_res->end) > - free = region_res->end - res->end; > - > - if (free >= to_alloc && strcmp(name, res->name) == 0) > - return __adjust_dev_dax_range(dev_dax, res, > - resource_size(res) + to_alloc); > - else if (free >= to_alloc && dev_size == 0) > - return __alloc_dev_dax_range(dev_dax, res->end + 1, > - to_alloc); > + if (!alloc && !next && res->end < region_res->end) > + alloc = min(region_res->end - res->end, to_alloc); > + > + if (!alloc) > + continue; > + > + if (adjust_ok(dev_dax, res)) { > + rc = __adjust_dev_dax_range(dev_dax, res, > + resource_size(res) + alloc); > + break; > + } > + rc = __alloc_dev_dax_range(dev_dax, res->end + 1, > + alloc); I am wondering if we should switch to: if (adjust_ok(...)) rc = __adjust_dev_dax_range(...); else rc = __alloc_dev_dax_range(...); And then a debug print at the end depicting whether and how did we grabbed space? Something like: dev_dbg(&dev_dax->dev, "%s(%d) %d", action, location, rc); Assuming we set @location to its values when we allocate space at the end, beginning or middle; and @action to whether we adjusted up/down or allocated new range. Essentially, something similar to namespaces scan_allocate() just to help troubleshoot? Regards, Joao _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
next prev parent reply other threads:[~2020-03-24 16:12 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 [this message] 2020-03-25 10:35 ` Joao Martins 2020-03-25 17:48 ` Dan Williams 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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