Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1662727 > unrolled thread

[PATCH v3 14/14] libnvdimm, pmem: disable dax flushing when pmem is fronting a volatile region

Started byDan Williams <dan.j.williams@intel.com>
First post2017-06-09 22:40 +0200
Last post2017-06-10 20:10 +0200
Articles 3 — 1 participant

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  [PATCH v3 14/14] libnvdimm,  pmem: disable dax flushing when pmem is fronting a volatile region Dan Williams <dan.j.williams@intel.com> - 2017-06-09 22:40 +0200
    Re: [PATCH v3 14/14] libnvdimm, pmem: disable dax flushing when pmem  is fronting a volatile region Dan Williams <dan.j.williams@intel.com> - 2017-06-10 01:30 +0200
    [PATCH v4 14/14] libnvdimm,  pmem: disable dax flushing when pmem is fronting a volatile region Dan Williams <dan.j.williams@intel.com> - 2017-06-10 20:10 +0200

#1662727 — [PATCH v3 14/14] libnvdimm, pmem: disable dax flushing when pmem is fronting a volatile region

FromDan Williams <dan.j.williams@intel.com>
Date2017-06-09 22:40 +0200
Subject[PATCH v3 14/14] libnvdimm, pmem: disable dax flushing when pmem is fronting a volatile region
Message-ID<tQyRj-6b1-11@gated-at.bofh.it>
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 <jack@suse.cz>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/nvdimm/pmem.c        |   13 ++++++++-----
 drivers/nvdimm/region_devs.c |    6 ++++++
 include/linux/libnvdimm.h    |    1 +
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 06f6c27ec1e9..5cac9fb39db8 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)
-		dev_warn(dev, "unable to guarantee persistence of writes\n");
+	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(&region_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__ */

[toc] | [next] | [standalone]

#1662821 — Re: [PATCH v3 14/14] libnvdimm, pmem: disable dax flushing when pmem is fronting a volatile region

FromDan Williams <dan.j.williams@intel.com>
Date2017-06-10 01:30 +0200
SubjectRe: [PATCH v3 14/14] libnvdimm, pmem: disable dax flushing when pmem is fronting a volatile region
Message-ID<tQBvQ-7Pk-15@gated-at.bofh.it>
In reply to#1662727
On Fri, Jun 9, 2017 at 1:25 PM, Dan Williams <dan.j.williams@intel.com> wrote:
> 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 <jack@suse.cz>
> Cc: Jeff Moyer <jmoyer@redhat.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Matthew Wilcox <mawilcox@microsoft.com>
> Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
>  drivers/nvdimm/pmem.c        |   13 ++++++++-----
>  drivers/nvdimm/region_devs.c |    6 ++++++
>  include/linux/libnvdimm.h    |    1 +
>  3 files changed, 15 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
> index 06f6c27ec1e9..5cac9fb39db8 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)
> -               dev_warn(dev, "unable to guarantee persistence of writes\n");
> +       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"); {

I sent this patch with local uncommitted changes. Will send a v2
shortly, and also update stg mail to abort if the tree is dirty.

[toc] | [prev] | [next] | [standalone]

#1662990 — [PATCH v4 14/14] libnvdimm, pmem: disable dax flushing when pmem is fronting a volatile region

FromDan Williams <dan.j.williams@intel.com>
Date2017-06-10 20:10 +0200
Subject[PATCH v4 14/14] libnvdimm, pmem: disable dax flushing when pmem is fronting a volatile region
Message-ID<tQSZH-2hW-5@gated-at.bofh.it>
In reply to#1662727
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 <jack@suse.cz>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
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(&region_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__ */

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web