summaryrefslogtreecommitdiff
path: root/Documentation
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2009-12-16 12:36:49 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-12-16 12:36:49 -0800
commitd4220f987cf473c65a342ca69e3eb13dea919a49 (patch)
treedbb004a9c805d6de3f6e3955398fee1084a29f16 /Documentation
parent61cf693159d6a968a7014e24905143f71ed8ddcf (diff)
parentf2c03debdfb387fa2e35cac6382779072b8b9209 (diff)
Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6
* 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (34 commits) HWPOISON: Remove stray phrase in a comment HWPOISON: Try to allocate migration page on the same node HWPOISON: Don't do early filtering if filter is disabled HWPOISON: Add a madvise() injector for soft page offlining HWPOISON: Add soft page offline support HWPOISON: Undefine short-hand macros after use to avoid namespace conflict HWPOISON: Use new shake_page in memory_failure HWPOISON: Use correct name for MADV_HWPOISON in documentation HWPOISON: mention HWPoison in Kconfig entry HWPOISON: Use get_user_page_fast in hwpoison madvise HWPOISON: add an interface to switch off/on all the page filters HWPOISON: add memory cgroup filter memcg: add accessor to mem_cgroup.css memcg: rename and export try_get_mem_cgroup_from_page() HWPOISON: add page flags filter mm: export stable page flags HWPOISON: limit hwpoison injector to known page types HWPOISON: add fs/device filters HWPOISON: return 0 to indicate success reliably HWPOISON: make semantics of IGNORED/DELAYED clear ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/testing/sysfs-memory-page-offline44
-rw-r--r--Documentation/vm/hwpoison.txt52
-rw-r--r--Documentation/vm/page-types.c15
3 files changed, 106 insertions, 5 deletions
diff --git a/Documentation/ABI/testing/sysfs-memory-page-offline b/Documentation/ABI/testing/sysfs-memory-page-offline
new file mode 100644
index 000000000000..e14703f12fdf
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-memory-page-offline
@@ -0,0 +1,44 @@
+What: /sys/devices/system/memory/soft_offline_page
+Date: Sep 2009
+KernelVersion: 2.6.33
+Contact: andi@firstfloor.org
+Description:
+ Soft-offline the memory page containing the physical address
+ written into this file. Input is a hex number specifying the
+ physical address of the page. The kernel will then attempt
+ to soft-offline it, by moving the contents elsewhere or
+ dropping it if possible. The kernel will then be placed
+ on the bad page list and never be reused.
+
+ The offlining is done in kernel specific granuality.
+ Normally it's the base page size of the kernel, but
+ this might change.
+
+ The page must be still accessible, not poisoned. The
+ kernel will never kill anything for this, but rather
+ fail the offline. Return value is the size of the
+ number, or a error when the offlining failed. Reading
+ the file is not allowed.
+
+What: /sys/devices/system/memory/hard_offline_page
+Date: Sep 2009
+KernelVersion: 2.6.33
+Contact: andi@firstfloor.org
+Description:
+ Hard-offline the memory page containing the physical
+ address written into this file. Input is a hex number
+ specifying the physical address of the page. The
+ kernel will then attempt to hard-offline the page, by
+ trying to drop the page or killing any owner or
+ triggering IO errors if needed. Note this may kill
+ any processes owning the page. The kernel will avoid
+ to access this page assuming it's poisoned by the
+ hardware.
+
+ The offlining is done in kernel specific granuality.
+ Normally it's the base page size of the kernel, but
+ this might change.
+
+ Return value is the size of the number, or a error when
+ the offlining failed.
+ Reading the file is not allowed.
diff --git a/Documentation/vm/hwpoison.txt b/Documentation/vm/hwpoison.txt
index 3ffadf8da61f..12f9ba20ccb7 100644
--- a/Documentation/vm/hwpoison.txt
+++ b/Documentation/vm/hwpoison.txt
@@ -92,16 +92,62 @@ PR_MCE_KILL_GET
Testing:
-madvise(MADV_POISON, ....)
+madvise(MADV_HWPOISON, ....)
(as root)
Poison a page in the process for testing
hwpoison-inject module through debugfs
- /sys/debug/hwpoison/corrupt-pfn
-Inject hwpoison fault at PFN echoed into this file
+/sys/debug/hwpoison/
+corrupt-pfn
+
+Inject hwpoison fault at PFN echoed into this file. This does
+some early filtering to avoid corrupted unintended pages in test suites.
+
+unpoison-pfn
+
+Software-unpoison page at PFN echoed into this file. This
+way a page can be reused again.
+This only works for Linux injected failures, not for real
+memory failures.
+
+Note these injection interfaces are not stable and might change between
+kernel versions
+
+corrupt-filter-dev-major
+corrupt-filter-dev-minor
+
+Only handle memory failures to pages associated with the file system defined
+by block device major/minor. -1U is the wildcard value.
+This should be only used for testing with artificial injection.
+
+corrupt-filter-memcg
+
+Limit injection to pages owned by memgroup. Specified by inode number
+of the memcg.
+
+Example:
+ mkdir /cgroup/hwpoison
+
+ usemem -m 100 -s 1000 &
+ echo `jobs -p` > /cgroup/hwpoison/tasks
+
+ memcg_ino=$(ls -id /cgroup/hwpoison | cut -f1 -d' ')
+ echo $memcg_ino > /debug/hwpoison/corrupt-filter-memcg
+
+ page-types -p `pidof init` --hwpoison # shall do nothing
+ page-types -p `pidof usemem` --hwpoison # poison its pages
+
+corrupt-filter-flags-mask
+corrupt-filter-flags-value
+
+When specified, only poison pages if ((page_flags & mask) == value).
+This allows stress testing of many kinds of pages. The page_flags
+are the same as in /proc/kpageflags. The flag bits are defined in
+include/linux/kernel-page-flags.h and documented in
+Documentation/vm/pagemap.txt
Architecture specific MCE injector
diff --git a/Documentation/vm/page-types.c b/Documentation/vm/page-types.c
index 7a7d9bab32ef..66e9358e2144 100644
--- a/Documentation/vm/page-types.c
+++ b/Documentation/vm/page-types.c
@@ -1,11 +1,22 @@
/*
* page-types: Tool for querying page flags
*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should find a copy of v2 of the GNU General Public License somewhere on
+ * your Linux system; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
* Copyright (C) 2009 Intel corporation
*
* Authors: Wu Fengguang <fengguang.wu@intel.com>
- *
- * Released under the General Public License (GPL).
*/
#define _LARGEFILE64_SOURCE