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>,
"Jérôme Glisse" <jglisse@redhat.com>,
"Dan Williams" <dan.j.williams@intel.com>,
"Ross Zwisler" <ross.zwisler@linux.intel.com>
Subject: [HMM v14 01/16] mm/free_hot_cold_page: catch ZONE_DEVICE pages
Date: Thu, 8 Dec 2016 11:39:29 -0500 [thread overview]
Message-ID: <1481215184-18551-2-git-send-email-jglisse@redhat.com> (raw)
In-Reply-To: <1481215184-18551-1-git-send-email-jglisse@redhat.com>
Catch page from ZONE_DEVICE in free_hot_cold_page(). This should never
happen as ZONE_DEVICE page must always have an elevated refcount.
This is safety-net to catch any refcounting issues in a sane way for any
ZONE_DEVICE pages.
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
---
mm/page_alloc.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0fbfead..09b2630 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2435,6 +2435,16 @@ void free_hot_cold_page(struct page *page, bool cold)
unsigned long pfn = page_to_pfn(page);
int migratetype;
+ /*
+ * This should never happen ! Page from ZONE_DEVICE always must have an
+ * active refcount. Complain about it and try to restore the refcount.
+ */
+ if (is_zone_device_page(page)) {
+ VM_BUG_ON_PAGE(is_zone_device_page(page), page);
+ page_ref_inc(page);
+ return;
+ }
+
if (!free_pcp_prepare(page))
return;
--
2.4.3
next prev parent reply other threads:[~2016-12-08 15:39 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-08 16:39 [HMM v14 00/16] HMM (Heterogeneous Memory Management) v14 Jérôme Glisse
2016-12-08 16:39 ` Jérôme Glisse [this message]
2016-12-08 16:39 ` [HMM v14 02/16] mm/memory/hotplug: convert device bool to int to allow for more flags v2 Jérôme Glisse
2016-12-08 16:39 ` [HMM v14 03/16] mm/ZONE_DEVICE/devmem_pages_remove: allow early removal of device memory Jérôme Glisse
2016-12-08 16:39 ` [HMM v14 04/16] mm/ZONE_DEVICE/free-page: callback when page is freed Jérôme Glisse
2016-12-08 16:39 ` [HMM v14 05/16] mm/ZONE_DEVICE/unaddressable: add support for un-addressable device memory Jérôme Glisse
2016-12-08 16:21 ` Dave Hansen
2016-12-08 16:39 ` Jerome Glisse
2016-12-08 20:07 ` Dave Hansen
2016-12-08 20:37 ` Jerome Glisse
2016-12-26 9:12 ` Anshuman Khandual
2016-12-26 19:02 ` Jerome Glisse
2016-12-08 16:39 ` [HMM v14 06/16] mm/ZONE_DEVICE/x86: " Jérôme Glisse
2016-12-08 16:39 ` [HMM v14 07/16] mm/hmm: heterogeneous memory management (HMM for short) Jérôme Glisse
2016-12-08 16:39 ` [HMM v14 08/16] mm/hmm/mirror: mirror process address space on device with HMM helpers Jérôme Glisse
2016-12-08 16:39 ` [HMM v14 09/16] mm/hmm/mirror: helper to snapshot CPU page table Jérôme Glisse
2016-12-08 16:39 ` [HMM v14 10/16] mm/hmm/mirror: device page fault handler Jérôme Glisse
2016-12-08 16:39 ` [HMM v14 11/16] mm/hmm/migrate: support un-addressable ZONE_DEVICE page in migration Jérôme Glisse
2016-12-08 16:39 ` [HMM v14 12/16] mm/hmm/migrate: add new boolean copy flag to migratepage() callback Jérôme Glisse
2016-12-08 16:39 ` [HMM v14 13/16] mm/hmm/migrate: new memory migration helper for use with device memory v2 Jérôme Glisse
2016-12-08 16:39 ` [HMM v14 14/16] mm/hmm/migrate: optimize page map once in vma being migrated Jérôme Glisse
2016-12-08 16:39 ` [HMM v14 15/16] mm/hmm/devmem: device driver helper to hotplug ZONE_DEVICE memory Jérôme Glisse
2016-12-08 16:39 ` [HMM v14 16/16] mm/hmm/devmem: dummy HMM device as an helper for " Jérôme Glisse
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