linux-toradex.git/mm/madvise.c, branch v2.6.35.2

HWPOISON: Add a madvise() injector for soft page offlining

2009-12-16T11:20:00+00:00

Process based injection is much easier to handle for test programs,
who can first bring a page into a specific state and then test.
So add a new MADV_SOFT_OFFLINE to soft offline a page, similar
to the existing hard offline injector.

Signed-off-by: Andi Kleen

HWPOISON: Use get_user_page_fast in hwpoison madvise

2009-12-16T11:20:00+00:00

The previous version didn't take the mmap_sem before calling gup(),
which is racy.

Use get_user_pages_fast() instead which doesn't need any locks.
This is also faster of course, but then it doesn't really matter
because this is just a testing path.

Based on report from Nick Piggin.
Cc: npiggin@suse.de

Signed-off-by: Andi Kleen

HWPOISON: Turn ref argument into flags argument

2009-12-16T11:19:57+00:00

Now that "ref" is just a boolean turn it into
a flags argument. First step is only a single flag
that makes the code's intention more clear, but more
may follow.

Signed-off-by: Andi Kleen

HWPOISON: avoid grabbing the page count multiple times during madvise injection

2009-12-16T11:19:57+00:00

If page is double referenced in madvise_hwpoison() and __memory_failure(),
remove_mapping() will fail because it expects page_count=2. Fix it by
not grabbing extra page count in __memory_failure().

Signed-off-by: Wu Fengguang 
Signed-off-by: Andi Kleen

Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6

2009-09-24T14:53:22+00:00

* 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (21 commits)
  HWPOISON: Enable error_remove_page on btrfs
  HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs
  HWPOISON: Add madvise() based injector for hardware poisoned pages v4
  HWPOISON: Enable error_remove_page for NFS
  HWPOISON: Enable .remove_error_page for migration aware file systems
  HWPOISON: The high level memory error handler in the VM v7
  HWPOISON: Add PR_MCE_KILL prctl to control early kill behaviour per process
  HWPOISON: shmem: call set_page_dirty() with locked page
  HWPOISON: Define a new error_remove_page address space op for async truncation
  HWPOISON: Add invalidate_inode_page
  HWPOISON: Refactor truncate to allow direct truncating of page v2
  HWPOISON: check and isolate corrupted free pages v2
  HWPOISON: Handle hardware poisoned pages in try_to_unmap
  HWPOISON: Use bitmask/action code for try_to_unmap behaviour
  HWPOISON: x86: Add VM_FAULT_HWPOISON handling to x86 page fault handler v2
  HWPOISON: Add poison check to page fault handling
  HWPOISON: Add basic support for poisoned pages in fault handler v3
  HWPOISON: Add new SIGBUS error codes for hardware poison signals
  HWPOISON: Add support for poison swap entries v2
  HWPOISON: Export some rmap vma locking to outside world
  ...

ksm: the mm interface to ksm

2009-09-22T14:17:31+00:00

This patch presents the mm interface to a dummy version of ksm.c, for
better scrutiny of that interface: the real ksm.c follows later.

When CONFIG_KSM is not set, madvise(2) reject MADV_MERGEABLE and
MADV_UNMERGEABLE with EINVAL, since that seems more helpful than
pretending that they can be serviced.  But when CONFIG_KSM=y, accept them
even if KSM is not currently running, and even on areas which KSM will not
touch (e.g.  hugetlb or shared file or special driver mappings).

Like other madvices, report ENOMEM despite success if any area in the
range is unmapped, and use EAGAIN to report out of memory.

Define vma flag VM_MERGEABLE to identify an area on which KSM may try
merging pages: leave it to ksm_madvise() to decide whether to set it.
Define mm flag MMF_VM_MERGEABLE to identify an mm which might contain
VM_MERGEABLE areas, to minimize callouts when forking or exiting.

Based upon earlier patches by Chris Wright and Izik Eidus.

Signed-off-by: Hugh Dickins 
Signed-off-by: Chris Wright 
Signed-off-by: Izik Eidus 
Cc: Michael Kerrisk 
Cc: Andrea Arcangeli 
Cc: Rik van Riel 
Cc: Wu Fengguang 
Cc: Balbir Singh 
Cc: Hugh Dickins 
Cc: KAMEZAWA Hiroyuki 
Cc: Lee Schermerhorn 
Cc: Avi Kivity 
Cc: Nick Piggin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ksm: first tidy up madvise_vma()

2009-09-22T14:17:31+00:00

madvise.c has several levels of switch statements, what to do in which?
Move MADV_DOFORK code down from madvise_vma() to madvise_behavior(), so
madvise_vma() can be a simple router, to madvise_behavior() by default.

vma->vm_flags is an unsigned long so use the same type for new_flags.  Add
missing comment lines to describe MADV_DONTFORK and MADV_DOFORK.

Signed-off-by: Hugh Dickins 
Signed-off-by: Chris Wright 
Signed-off-by: Izik Eidus 
Cc: Andrea Arcangeli 
Cc: Rik van Riel 
Cc: Wu Fengguang 
Cc: Balbir Singh 
Cc: Hugh Dickins 
Cc: KAMEZAWA Hiroyuki 
Cc: Lee Schermerhorn 
Cc: Avi Kivity 
Cc: Nick Piggin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

HWPOISON: Add madvise() based injector for hardware poisoned pages v4

2009-09-16T09:50:17+00:00

Impact: optional, useful for debugging

Add a new madvice sub command to inject poison for some
pages in a process' address space.  This is useful for
testing the poison page handling.

This patch can allow root to tie up large amounts of memory.
I got feedback from container developers and they didn't see any
problem.

v2: Use write flag for get_user_pages to make sure to always get
a fresh page
v3: Don't request write mapping (Fengguang Wu)
v4: Move MADV_* number to avoid conflict with KSM (Hugh Dickins)

Signed-off-by: Andi Kleen

mm: madvise(): correct return code

2009-06-17T02:47:40+00:00

The posix_madvise() function succeeds (and does nothing) when called with
parameters (NULL, 0, -1); according to LSB tests, it should fail with
EINVAL because -1 is not a valid flag.

When called with a valid address and size, it correctly fails.

So perform an initial check for valid flags first.

Reported-by: Jiri Dluhos 
Signed-off-by: Nick Piggin 
Reviewed-and-Tested-by: WANG Cong 
Cc: Michael Kerrisk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

readahead: move max_sane_readahead() calls into force_page_cache_readahead()

2009-06-17T02:47:28+00:00

Impact: code simplification.

Cc: Nick Piggin 
Signed-off-by: Wu Fengguang 
Cc: Ying Han 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds