From: "Jérôme Glisse" <jglisse@redhat.com>
To: akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org
Cc: "John Hubbard" <jhubbard@nvidia.com>,
"David Nellans" <dnellans@nvidia.com>,
"Jérôme Glisse" <jglisse@redhat.com>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
"Dan Williams" <dan.j.williams@intel.com>,
"Ross Zwisler" <ross.zwisler@linux.intel.com>
Subject: [HMM 08/15] mm/ZONE_DEVICE: special case put_page() for device private pages
Date: Mon, 22 May 2017 12:51:59 -0400 [thread overview]
Message-ID: <20170522165206.6284-9-jglisse@redhat.com> (raw)
In-Reply-To: <20170522165206.6284-1-jglisse@redhat.com>
A ZONE_DEVICE page that reach a refcount of 1 is free ie no longer
have any user. For device private pages this is important to catch
and thus we need to special case put_page() for this.
Signed-off-by: JA(C)rA'me Glisse <jglisse@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
---
include/linux/mm.h | 30 ++++++++++++++++++++++++++++++
kernel/memremap.c | 1 -
2 files changed, 30 insertions(+), 1 deletion(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a825dab..11f7bac 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -23,6 +23,7 @@
#include <linux/page_ext.h>
#include <linux/err.h>
#include <linux/page_ref.h>
+#include <linux/memremap.h>
struct mempolicy;
struct anon_vma;
@@ -795,6 +796,20 @@ static inline bool is_device_private_page(const struct page *page)
return ((page_zonenum(page) == ZONE_DEVICE) &&
(page->pgmap->type == MEMORY_DEVICE_PRIVATE));
}
+
+static inline void put_zone_device_private_page(struct page *page)
+{
+ int count = page_ref_dec_return(page);
+
+ /*
+ * If refcount is 1 then page is freed and refcount is stable as nobody
+ * holds a reference on the page.
+ */
+ if (count == 1)
+ page->pgmap->page_free(page, page->pgmap->data);
+ else if (!count)
+ __put_page(page);
+}
#else
static inline bool is_zone_device_page(const struct page *page)
{
@@ -805,6 +820,10 @@ static inline bool is_device_private_page(const struct page *page)
{
return false;
}
+
+static inline void put_zone_device_private_page(struct page *page)
+{
+}
#endif
static inline void get_page(struct page *page)
@@ -822,6 +841,17 @@ static inline void put_page(struct page *page)
{
page = compound_head(page);
+ /*
+ * For private device pages we need to catch refcount transition from
+ * 2 to 1, when refcount reach one it means the private device page is
+ * free and we need to inform the device driver through callback. See
+ * include/linux/memremap.h and HMM for details.
+ */
+ if (unlikely(is_device_private_page(page))) {
+ put_zone_device_private_page(page);
+ return;
+ }
+
if (put_page_testzero(page))
__put_page(page);
}
diff --git a/kernel/memremap.c b/kernel/memremap.c
index dbdb656..71f6f28 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -11,7 +11,6 @@
* General Public License for more details.
*/
#include <linux/radix-tree.h>
-#include <linux/memremap.h>
#include <linux/device.h>
#include <linux/types.h>
#include <linux/pfn_t.h>
--
2.9.3
--
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next prev parent reply other threads:[~2017-05-22 16:52 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-22 16:51 [HMM 00/15] HMM (Heterogeneous Memory Management) v22 Jérôme Glisse
2017-05-22 16:51 ` [HMM 01/15] hmm: heterogeneous memory management documentation Jérôme Glisse
2017-05-22 16:51 ` [HMM 02/15] mm/hmm: heterogeneous memory management (HMM for short) v3 Jérôme Glisse
2017-05-22 16:51 ` [HMM 03/15] mm/hmm/mirror: mirror process address space on device with HMM helpers v3 Jérôme Glisse
2017-05-22 16:51 ` [HMM 04/15] mm/hmm/mirror: helper to snapshot CPU page table v3 Jérôme Glisse
2017-05-22 16:51 ` [HMM 05/15] mm/hmm/mirror: device page fault handler Jérôme Glisse
2017-05-22 16:51 ` [HMM 06/15] mm/memory_hotplug: introduce add_pages Jérôme Glisse
2017-05-22 16:51 ` [HMM 07/15] mm/ZONE_DEVICE: new type of ZONE_DEVICE for unaddressable memory v2 Jérôme Glisse
2017-05-22 21:17 ` Dan Williams
2017-05-23 21:36 ` [HMM 07/18] mm/ZONE_DEVICE: new type of ZONE_DEVICE for unaddressable memory v3 Jérôme Glisse
2017-05-23 8:36 ` [HMM 07/15] mm/ZONE_DEVICE: new type of ZONE_DEVICE for unaddressable memory v2 kbuild test robot
2017-05-22 16:51 ` Jérôme Glisse [this message]
2017-05-22 19:29 ` [HMM 08/15] mm/ZONE_DEVICE: special case put_page() for device private pages Dan Williams
2017-05-22 20:14 ` Jerome Glisse
2017-05-22 20:19 ` Dan Williams
2017-05-22 21:14 ` Jerome Glisse
2017-05-22 20:22 ` Hugh Dickins
2017-05-22 21:17 ` Jerome Glisse
2017-05-23 9:34 ` kbuild test robot
2017-05-23 13:23 ` Kirill A. Shutemov
2017-05-23 21:37 ` [HMM 08/18] mm/ZONE_DEVICE: special case put_page() for device private pages v2 Jérôme Glisse
2017-05-22 16:52 ` [HMM 09/15] mm/hmm/devmem: device memory hotplug using ZONE_DEVICE v4 Jérôme Glisse
2017-05-23 21:37 ` [HMM 09/18] mm/hmm/devmem: device memory hotplug using ZONE_DEVICE v5 Jérôme Glisse
2017-05-22 16:52 ` [HMM 10/15] mm/hmm/devmem: dummy HMM device for ZONE_DEVICE memory v3 Jérôme Glisse
2017-05-22 16:52 ` [HMM 11/15] mm/migrate: new migrate mode MIGRATE_SYNC_NO_COPY Jérôme Glisse
2017-05-22 16:52 ` [HMM 12/15] mm/migrate: new memory migration helper for use with device memory v4 Jérôme Glisse
2017-05-23 18:07 ` Reza Arbab
2017-06-27 0:07 ` Evgeny Baskakov
2017-06-30 23:19 ` Evgeny Baskakov
2017-07-01 0:57 ` Jerome Glisse
2017-07-01 2:06 ` Evgeny Baskakov
2017-07-10 22:59 ` Evgeny Baskakov
2017-07-10 23:43 ` Jerome Glisse
2017-07-11 0:17 ` Evgeny Baskakov
2017-07-11 0:54 ` Jerome Glisse
2017-07-20 21:05 ` Evgeny Baskakov
2017-07-10 23:44 ` Evgeny Baskakov
2017-07-11 18:29 ` Jerome Glisse
2017-07-11 18:42 ` Evgeny Baskakov
2017-07-11 18:49 ` Jerome Glisse
2017-07-11 19:35 ` Evgeny Baskakov
2017-07-13 20:16 ` Jerome Glisse
2017-07-14 5:32 ` Evgeny Baskakov
2017-07-14 19:43 ` Evgeny Baskakov
2017-07-15 0:55 ` Jerome Glisse
2017-07-15 5:04 ` Evgeny Baskakov
2017-07-21 1:00 ` Evgeny Baskakov
2017-07-21 1:33 ` Jerome Glisse
2017-07-21 22:01 ` Evgeny Baskakov
2017-07-25 22:45 ` Evgeny Baskakov
2017-07-26 19:14 ` Jerome Glisse
2017-05-22 16:52 ` [HMM 13/15] mm/migrate: migrate_vma() unmap page from vma while collecting pages Jérôme Glisse
2017-05-22 16:52 ` [HMM 14/15] mm/migrate: support un-addressable ZONE_DEVICE page in migration v2 Jérôme Glisse
2017-05-22 16:52 ` [HMM 15/15] mm/migrate: allow migrate_vma() to alloc new page on empty entry v2 Jérôme Glisse
2017-05-23 22:02 ` [HMM 00/15] HMM (Heterogeneous Memory Management) v22 Jerome Glisse
2017-05-23 22:05 ` Andrew Morton
2017-05-24 1:55 ` Balbir Singh
2017-05-24 17:53 ` Jerome Glisse
2017-06-01 2:04 ` Balbir Singh
2017-06-01 22:38 ` Jerome Glisse
2017-06-03 9:18 ` Balbir Singh
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