From: Dan Williams <dan.j.williams@intel.com>
To: linux-nvdimm@lists.01.org
Cc: "Jan Kara" <jack@suse.cz>, "Christoph Hellwig" <hch@lst.de>,
"Jérôme Glisse" <jglisse@redhat.com>,
"Matthew Wilcox" <mawilcox@microsoft.com>,
"Naoya Horiguchi" <n-horiguchi@ah.jp.nec.com>,
"Ross Zwisler" <ross.zwisler@linux.intel.com>,
linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, jack@suse.cz
Subject: [PATCH v4 11/12] mm, memory_failure: Teach memory_failure() about dev_pagemap pages
Date: Fri, 08 Jun 2018 16:51:19 -0700 [thread overview]
Message-ID: <152850187949.38390.1012249765651998342.stgit@dwillia2-desk3.amr.corp.intel.com> (raw)
In-Reply-To: <152850182079.38390.8280340535691965744.stgit@dwillia2-desk3.amr.corp.intel.com>
mce: Uncorrected hardware memory error in user-access at af34214200
{1}[Hardware Error]: It has been corrected by h/w and requires no further action
mce: [Hardware Error]: Machine check events logged
{1}[Hardware Error]: event severity: corrected
Memory failure: 0xaf34214: reserved kernel page still referenced by 1 users
[..]
Memory failure: 0xaf34214: recovery action for reserved kernel page: Failed
mce: Memory error not recovered
In contrast to typical memory, dev_pagemap pages may be dax mapped. With
dax there is no possibility to map in another page dynamically since dax
establishes 1:1 physical address to file offset associations. Also
dev_pagemap pages associated with NVDIMM / persistent memory devices can
internal remap/repair addresses with poison. While memory_failure()
assumes that it can discard typical poisoned pages and keep them
unmapped indefinitely, dev_pagemap pages may be returned to service
after the error is cleared.
Teach memory_failure() to detect and handle MEMORY_DEVICE_HOST
dev_pagemap pages that have poison consumed by userspace. Mark the
memory as UC instead of unmapping it completely to allow ongoing access
via the device driver (nd_pmem). Later, nd_pmem will grow support for
marking the page back to WB when the error is cleared.
Cc: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
include/linux/mm.h | 1
mm/memory-failure.c | 127 +++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 128 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1ac1f06a4be6..566c972e03e7 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2669,6 +2669,7 @@ enum mf_action_page_type {
MF_MSG_TRUNCATED_LRU,
MF_MSG_BUDDY,
MF_MSG_BUDDY_2ND,
+ MF_MSG_DAX,
MF_MSG_UNKNOWN,
};
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 42a193ee14d3..a5912b27fea7 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -55,6 +55,7 @@
#include <linux/hugetlb.h>
#include <linux/memory_hotplug.h>
#include <linux/mm_inline.h>
+#include <linux/memremap.h>
#include <linux/kfifo.h>
#include <linux/ratelimit.h>
#include "internal.h"
@@ -513,6 +514,7 @@ static const char * const action_page_types[] = {
[MF_MSG_TRUNCATED_LRU] = "already truncated LRU page",
[MF_MSG_BUDDY] = "free buddy page",
[MF_MSG_BUDDY_2ND] = "free buddy page (2nd try)",
+ [MF_MSG_DAX] = "dax page",
[MF_MSG_UNKNOWN] = "unknown page",
};
@@ -1112,6 +1114,126 @@ static int memory_failure_hugetlb(unsigned long pfn, int flags)
return res;
}
+static unsigned long dax_mapping_size(struct page *page)
+{
+ struct address_space *mapping = page->mapping;
+ pgoff_t pgoff = page_to_pgoff(page);
+ struct vm_area_struct *vma;
+ unsigned long size = 0;
+
+ i_mmap_lock_read(mapping);
+ vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
+ unsigned long address = vma_address(page, vma);
+ pgd_t *pgd;
+ p4d_t *p4d;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+
+ pgd = pgd_offset(vma->vm_mm, address);
+ if (!pgd_present(*pgd))
+ continue;
+ p4d = p4d_offset(pgd, address);
+ if (!p4d_present(*p4d))
+ continue;
+ pud = pud_offset(p4d, address);
+ if (!pud_present(*pud))
+ continue;
+ if (pud_devmap(*pud)) {
+ size = PUD_SIZE;
+ break;
+ }
+ pmd = pmd_offset(pud, address);
+ if (!pmd_present(*pmd))
+ continue;
+ if (pmd_devmap(*pmd)) {
+ size = PMD_SIZE;
+ break;
+ }
+ pte = pte_offset_map(pmd, address);
+ if (!pte_present(*pte))
+ continue;
+ if (pte_devmap(*pte)) {
+ size = PAGE_SIZE;
+ break;
+ }
+ }
+ i_mmap_unlock_read(mapping);
+
+ return size;
+}
+
+static int memory_failure_dev_pagemap(unsigned long pfn, int flags,
+ struct dev_pagemap *pgmap)
+{
+ const bool unmap_success = true;
+ unsigned long size;
+ struct page *page;
+ LIST_HEAD(tokill);
+ int rc = -EBUSY;
+ loff_t start;
+
+ /*
+ * Prevent the inode from being freed while we are interrogating
+ * the address_space, typically this would be handled by
+ * lock_page(), but dax pages do not use the page lock.
+ */
+ page = dax_lock_page(pfn);
+ if (!page)
+ goto out;
+
+ if (hwpoison_filter(page)) {
+ rc = 0;
+ goto unlock;
+ }
+
+ switch (pgmap->type) {
+ case MEMORY_DEVICE_PRIVATE:
+ case MEMORY_DEVICE_PUBLIC:
+ /*
+ * TODO: Handle HMM pages which may need coordination
+ * with device-side memory.
+ */
+ goto unlock;
+ default:
+ break;
+ }
+
+ /*
+ * If the page is not mapped in userspace then report it as
+ * unhandled.
+ */
+ size = dax_mapping_size(page);
+ if (!size) {
+ pr_err("Memory failure: %#lx: failed to unmap page\n", pfn);
+ goto unlock;
+ }
+
+ SetPageHWPoison(page);
+
+ /*
+ * Unlike System-RAM there is no possibility to swap in a
+ * different physical page at a given virtual address, so all
+ * userspace consumption of ZONE_DEVICE memory necessitates
+ * SIGBUS (i.e. MF_MUST_KILL)
+ */
+ flags |= MF_ACTION_REQUIRED | MF_MUST_KILL;
+ collect_procs(page, &tokill, flags & MF_ACTION_REQUIRED);
+
+ start = (page->index << PAGE_SHIFT) & ~(size - 1);
+ unmap_mapping_range(page->mapping, start, start + size, 0);
+
+ kill_procs(&tokill, flags & MF_MUST_KILL, !unmap_success, ilog2(size),
+ pfn, flags);
+ rc = 0;
+unlock:
+ dax_unlock_page(page);
+out:
+ put_dev_pagemap(pgmap);
+ action_result(pfn, MF_MSG_DAX, rc ? MF_FAILED : MF_RECOVERED);
+ return rc;
+}
+
/**
* memory_failure - Handle memory failure of a page.
* @pfn: Page Number of the corrupted page
@@ -1134,6 +1256,7 @@ int memory_failure(unsigned long pfn, int flags)
struct page *p;
struct page *hpage;
struct page *orig_head;
+ struct dev_pagemap *pgmap;
int res;
unsigned long page_flags;
@@ -1146,6 +1269,10 @@ int memory_failure(unsigned long pfn, int flags)
return -ENXIO;
}
+ pgmap = get_dev_pagemap(pfn, NULL);
+ if (pgmap)
+ return memory_failure_dev_pagemap(pfn, flags, pgmap);
+
p = pfn_to_page(pfn);
if (PageHuge(p))
return memory_failure_hugetlb(pfn, flags);
next prev parent reply other threads:[~2018-06-08 23:51 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-08 23:50 [PATCH v4 00/12] mm: Teach memory_failure() about ZONE_DEVICE pages Dan Williams
2018-06-08 23:50 ` [PATCH v4 01/12] device-dax: Convert to vmf_insert_mixed and vm_fault_t Dan Williams
2018-06-08 23:50 ` [PATCH v4 02/12] device-dax: Cleanup vm_fault de-reference chains Dan Williams
2018-06-11 17:12 ` Laurent Dufour
2018-06-11 17:14 ` Dan Williams
2018-06-08 23:50 ` [PATCH v4 03/12] device-dax: Enable page_mapping() Dan Williams
2018-06-08 23:50 ` [PATCH v4 04/12] device-dax: Set page->index Dan Williams
2018-06-08 23:50 ` [PATCH v4 05/12] filesystem-dax: " Dan Williams
2018-06-08 23:50 ` [PATCH v4 06/12] mm, madvise_inject_error: Let memory_failure() optionally take a page reference Dan Williams
2018-06-08 23:50 ` [PATCH v4 07/12] x86/mm/pat: Prepare {reserve, free}_memtype() for "decoy" addresses Dan Williams
2018-06-08 23:51 ` [PATCH v4 08/12] x86/memory_failure: Introduce {set, clear}_mce_nospec() Dan Williams
2018-06-08 23:51 ` [PATCH v4 09/12] mm, memory_failure: Pass page size to kill_proc() Dan Williams
2018-06-08 23:51 ` [PATCH v4 10/12] filesystem-dax: Introduce dax_lock_page() Dan Williams
2018-06-11 15:41 ` Jan Kara
2018-06-11 16:48 ` Dan Williams
2018-06-12 18:07 ` Ross Zwisler
2018-07-04 15:20 ` Dan Williams
2018-07-04 15:17 ` Dan Williams
2018-06-12 18:15 ` Ross Zwisler
2018-07-04 15:11 ` Dan Williams
2018-06-08 23:51 ` Dan Williams [this message]
2018-06-11 15:50 ` [PATCH v4 11/12] mm, memory_failure: Teach memory_failure() about dev_pagemap pages Jan Kara
2018-06-11 16:45 ` Dan Williams
2018-06-12 20:14 ` Ross Zwisler
2018-06-12 23:38 ` Dan Williams
2018-06-08 23:51 ` [PATCH v4 12/12] libnvdimm, pmem: Restore page attributes when clearing errors Dan Williams
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