From db58028ee4e360430de8e3b48f657dc798ee6591 Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Mon, 26 Sep 2016 11:06:50 -0700 Subject: [PATCH] nvdimm: reduce duplicated wpq flushes Existing implemenetation writes to all the flush hint addresses for a given ND region. This is not necessary as the flushes are per imc and not per DIMM. Search the mappings and clear out the duplicates at init to avoid multiple flush to the same imc. Signed-off-by: Dave Jiang Signed-off-by: Dan Williams --- drivers/nvdimm/region_devs.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c index 4c0ac4a..f9d58c2 100644 --- a/drivers/nvdimm/region_devs.c +++ b/drivers/nvdimm/region_devs.c @@ -70,7 +70,7 @@ static int nvdimm_map_flush(struct device *dev, struct nvdimm *nvdimm, int dimm, int nd_region_activate(struct nd_region *nd_region) { - int i, num_flush = 0; + int i, j, num_flush = 0; struct nd_region_data *ndrd; struct device *dev = &nd_region->dev; size_t flush_data_size = sizeof(void *); @@ -107,6 +107,21 @@ int nd_region_activate(struct nd_region *nd_region) return rc; } + /* + * Clear out entries that are duplicates. This should prevent the + * extra flushings. + */ + for (i = 0; i < nd_region->ndr_mappings - 1; i++) { + /* ignore if NULL already */ + if (!ndrd_get_flush_wpq(ndrd, i, 0)) + continue; + + for (j = i + 1; j < nd_region->ndr_mappings; j++) + if (ndrd_get_flush_wpq(ndrd, i, 0) == + ndrd_get_flush_wpq(ndrd, j, 0)) + ndrd_set_flush_wpq(ndrd, j, 0, NULL); + } + return 0; } -- 2.7.4