From 0b277961f4484fb3f142caaa1dd1748cb0b2cbee Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 9 Jun 2017 09:46:50 -0700 Subject: libnvdimm, pmem: disable dax flushing when pmem is fronting a volatile region The pmem driver attaches to both persistent and volatile memory ranges advertised by the ACPI NFIT. When the region is volatile it is redundant to spend cycles flushing caches at fsync(). Check if the hosting region is volatile and do not set dax_write_cache() if it is. Cc: Jan Kara Cc: Jeff Moyer Cc: Christoph Hellwig Cc: Matthew Wilcox Cc: Ross Zwisler Signed-off-by: Dan Williams --- drivers/nvdimm/pmem.c | 13 ++++++++----- drivers/nvdimm/region_devs.c | 6 ++++++ 2 files changed, 14 insertions(+), 5 deletions(-) (limited to 'drivers/nvdimm') diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 7339d184070e..e7a40f77f729 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -284,10 +284,10 @@ static int pmem_attach_disk(struct device *dev, struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev); struct nd_region *nd_region = to_nd_region(dev->parent); struct vmem_altmap __altmap, *altmap = NULL; + int nid = dev_to_node(dev), fua, wbc; struct resource *res = &nsio->res; struct nd_pfn *nd_pfn = NULL; struct dax_device *dax_dev; - int nid = dev_to_node(dev); struct nd_pfn_sb *pfn_sb; struct pmem_device *pmem; struct resource pfn_res; @@ -314,9 +314,12 @@ static int pmem_attach_disk(struct device *dev, dev_set_drvdata(dev, pmem); pmem->phys_addr = res->start; pmem->size = resource_size(res); - if (!IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) - || nvdimm_has_flush(nd_region) < 0) + fua = nvdimm_has_flush(nd_region); + if (!IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) || fua < 0) { dev_warn(dev, "unable to guarantee persistence of writes\n"); + fua = 0; + } + wbc = nvdimm_has_cache(nd_region); if (!devm_request_mem_region(dev, res->start, resource_size(res), dev_name(&ndns->dev))) { @@ -360,7 +363,7 @@ static int pmem_attach_disk(struct device *dev, return PTR_ERR(addr); pmem->virt_addr = addr; - blk_queue_write_cache(q, true, true); + blk_queue_write_cache(q, wbc, fua); blk_queue_make_request(q, pmem_make_request); blk_queue_physical_block_size(q, PAGE_SIZE); blk_queue_max_hw_sectors(q, UINT_MAX); @@ -390,7 +393,7 @@ static int pmem_attach_disk(struct device *dev, put_disk(disk); return -ENOMEM; } - dax_write_cache(dax_dev, true); + dax_write_cache(dax_dev, wbc); pmem->dax_dev = dax_dev; gendev = disk_to_dev(disk); diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c index 53a64a16aba4..0c3b089b280a 100644 --- a/drivers/nvdimm/region_devs.c +++ b/drivers/nvdimm/region_devs.c @@ -1060,6 +1060,12 @@ int nvdimm_has_flush(struct nd_region *nd_region) } EXPORT_SYMBOL_GPL(nvdimm_has_flush); +int nvdimm_has_cache(struct nd_region *nd_region) +{ + return is_nd_pmem(&nd_region->dev); +} +EXPORT_SYMBOL_GPL(nvdimm_has_cache); + void __exit nd_region_devs_exit(void) { ida_destroy(®ion_ida); -- cgit v1.2.3