Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932263AbdDQTSB (ORCPT ); Mon, 17 Apr 2017 15:18:01 -0400 Received: from mga03.intel.com ([134.134.136.65]:38048 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757416AbdDQTRs (ORCPT ); Mon, 17 Apr 2017 15:17:48 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.37,215,1488873600"; d="scan'208";a="90539914" Subject: [resend PATCH v2 33/33] libnvdimm, pmem: disable dax flushing when pmem is fronting a volatile region From: Dan Williams To: linux-nvdimm@ml01.01.org Cc: Jan Kara , dm-devel@redhat.com, Matthew Wilcox , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, Jeff Moyer , linux-fsdevel@vger.kernel.org, Ross Zwisler , hch@lst.de Date: Mon, 17 Apr 2017 12:11:49 -0700 Message-ID: <149245630894.10206.4512506206746702195.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <149245612770.10206.15496018295337908594.stgit@dwillia2-desk3.amr.corp.intel.com> References: <149245612770.10206.15496018295337908594.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: 3103 Lines: 81 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 --- drivers/nvdimm/pmem.c | 9 +++++++-- drivers/nvdimm/region_devs.c | 6 ++++++ include/linux/libnvdimm.h | 1 + 3 files changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index b000c6db5731..42876a75dab8 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -275,6 +275,7 @@ static int pmem_attach_disk(struct device *dev, struct vmem_altmap __altmap, *altmap = NULL; struct resource *res = &nsio->res; struct nd_pfn *nd_pfn = NULL; + int has_flush, fua = 0, wbc; struct dax_device *dax_dev; int nid = dev_to_node(dev); struct nd_pfn_sb *pfn_sb; @@ -302,8 +303,12 @@ static int pmem_attach_disk(struct device *dev, dev_set_drvdata(dev, pmem); pmem->phys_addr = res->start; pmem->size = resource_size(res); - if (nvdimm_has_flush(nd_region) < 0) + has_flush = nvdimm_has_flush(nd_region); + if (has_flush < 0) dev_warn(dev, "unable to guarantee persistence of writes\n"); + else + fua = has_flush; + wbc = nvdimm_has_cache(nd_region); if (!devm_request_mem_region(dev, res->start, resource_size(res), dev_name(&ndns->dev))) { @@ -344,7 +349,7 @@ 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 2df259010720..a085f7094b76 100644 --- a/drivers/nvdimm/region_devs.c +++ b/drivers/nvdimm/region_devs.c @@ -989,6 +989,12 @@ 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 a98004745768..b733030107bb 100644 --- a/include/linux/libnvdimm.h +++ b/include/linux/libnvdimm.h @@ -162,6 +162,7 @@ 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); #ifdef CONFIG_ARCH_HAS_PMEM_API void arch_memcpy_to_pmem(void *dst, void *src, unsigned size); #define ARCH_MEMREMAP_PMEM MEMREMAP_WB