Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751712AbdFJSBI (ORCPT ); Sat, 10 Jun 2017 14:01:08 -0400 Received: from mga14.intel.com ([192.55.52.115]:5445 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751137AbdFJSBG (ORCPT ); Sat, 10 Jun 2017 14:01:06 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.39,324,1493708400"; d="scan'208";a="112805376" Subject: [PATCH v4 14/14] libnvdimm, pmem: disable dax flushing when pmem is fronting a volatile region From: Dan Williams To: linux-nvdimm@lists.01.org Cc: Jan Kara , dm-devel@redhat.com, Matthew Wilcox , x86@kernel.org, linux-kernel@vger.kernel.org, Jeff Moyer , viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, Ross Zwisler , hch@lst.de Date: Sat, 10 Jun 2017 10:54:37 -0700 Message-ID: <149711711307.40705.7075246631946565829.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <149703990158.20620.16257541455791191783.stgit@dwillia2-desk3.amr.corp.intel.com> References: <149703990158.20620.16257541455791191783.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.17.1-9-g687f MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3315 Lines: 87 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 QUEUE_FLAG_WC if it is. Cc: Jan Kara Cc: Jeff Moyer Cc: Christoph Hellwig Cc: Matthew Wilcox Cc: Ross Zwisler Signed-off-by: Dan Williams --- Changes since v3: * Fix compile error. drivers/nvdimm/pmem.c | 11 +++++++---- drivers/nvdimm/region_devs.c | 6 ++++++ include/linux/libnvdimm.h | 1 + 3 files changed, 14 insertions(+), 4 deletions(-) diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 06f6c27ec1e9..f39e095dd46d 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -279,10 +279,10 @@ 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; @@ -308,9 +308,12 @@ 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))) { @@ -354,7 +357,7 @@ 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); 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); diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h index b2f659bd661d..a8ee1d0afd70 100644 --- a/include/linux/libnvdimm.h +++ b/include/linux/libnvdimm.h @@ -165,4 +165,5 @@ void nd_region_release_lane(struct nd_region *nd_region, unsigned int lane); u64 nd_fletcher64(void *addr, size_t len, bool le); void nvdimm_flush(struct nd_region *nd_region); int nvdimm_has_flush(struct nd_region *nd_region); +int nvdimm_has_cache(struct nd_region *nd_region); #endif /* __LIBNVDIMM_H__ */