From: Ocean He <[email protected]> There is no need to finish entire loop to execute NDD_ALIASING bit test against every nvdimm->flags. In practice, all the nd_mapping->nvdimm have the same flags. So it's safe to return ND_DEVICE_NAMESPACE_PMEM if the NDD_ALIASING bit is found inside the loop, while saving a few cpu cycles.
Signed-off-by: Ocean He <[email protected]> --- v1: https://lkml.org/lkml/2018/8/19/4 v2: Per Vishal's comments in patch v1, remove 'alias' variable. In the loop, just return ND_DEVICE_NAMESPACE_PMEM if the NDD_ALIASING bit is found for any mapping. Outside the loop, simply return ND_DEVICE_NAMESPACE_IO. The following test pass on Lenovo ThinkSystem SR630 based on 4.19-rc1. # ndctl create-namespace -r region0 -s 1g -t pmem -m fsdax # ndctl create-namespace -r region0 -s 1g -t pmem -m sector # ndctl create-namespace -r region0 -s 1g -t pmem -m devdax # ndctl list [ { "dev":"namespace0.2", "mode":"devdax", "map":"dev", "size":1054867456, "uuid":"fc3a2126-9b8e-4ab4-baa4-a3ec7f62a326", "raw_uuid":"eadc6965-daee-48c5-a0ae-1865ee0c8573", "chardev":"dax0.2", "numa_node":0 }, { "dev":"namespace0.1", "mode":"sector", "size":1071616000, "uuid":"0d81d040-93a1-45c6-9791-3dbb7b5f89d2", "raw_uuid":"2b1b29e6-0510-4dcf-9902-43b77ccb9df5", "sector_size":4096, "blockdev":"pmem0.1s", "numa_node":0 }, { "dev":"namespace0.0", "mode":"fsdax", "map":"dev", "size":1054867456, "uuid":"cbff92ed-cd45-4d24-9353-7a56d42122b1", "raw_uuid":"f6ea1001-5ef0-4942-889a-99005079ab5d", "sector_size":512, "blockdev":"pmem0", "numa_node":0 } ] # reboot and OS could boot up normally # ndctl destroy-namespace namespace0.2 -f # ndctl destroy-namespace namespace0.1 -f # ndctl destroy-namespace namespace0.0 -f drivers/nvdimm/region_devs.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c index fa37afc..16ee153 100644 --- a/drivers/nvdimm/region_devs.c +++ b/drivers/nvdimm/region_devs.c @@ -228,19 +228,18 @@ void nd_blk_region_set_provider_data(struct nd_blk_region *ndbr, void *data) int nd_region_to_nstype(struct nd_region *nd_region) { if (is_memory(&nd_region->dev)) { - u16 i, alias; + u16 i; - for (i = 0, alias = 0; i < nd_region->ndr_mappings; i++) { + for (i = 0; i < nd_region->ndr_mappings; i++) { struct nd_mapping *nd_mapping = &nd_region->mapping[i]; struct nvdimm *nvdimm = nd_mapping->nvdimm; if (test_bit(NDD_ALIASING, &nvdimm->flags)) - alias++; + return ND_DEVICE_NAMESPACE_PMEM; } - if (alias) - return ND_DEVICE_NAMESPACE_PMEM; - else - return ND_DEVICE_NAMESPACE_IO; + + return ND_DEVICE_NAMESPACE_IO; + } else if (is_nd_blk(&nd_region->dev)) { return ND_DEVICE_NAMESPACE_BLK; } -- 1.8.3.1 _______________________________________________ Linux-nvdimm mailing list [email protected] https://lists.01.org/mailman/listinfo/linux-nvdimm
