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  1. 01 7月, 2006 1 次提交
  3. 28 6月, 2006 1 次提交
  5. 23 6月, 2006 5 次提交
    • A
      [PATCH] initialise total_memory() earlier · bd1e22b8
      由 Andrew Morton 提交于 
      Initialise total_memory earlier in boot.  Because if for some reason we run
page reclaim early in boot, we don't want total_memory to be zero when we use
it as a divisor.

And rename total_memory to vm_total_pages to avoid naming clashes with
architectures.

Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Martin Bligh <mbligh@google.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      bd1e22b8
    • C
      [PATCH] mm: fix swap unused warning · bd96b9eb
      由 Con Kolivas 提交于 
      If CONFIG_SWAP is not defined we get:

mm/vmscan.c: In function ‘remove_mapping’:
mm/vmscan.c:387: warning: unused variable ‘swap’

Convert defines in swap.h into blank inline functions to fix this warning
and be consistent.
Signed-off-by: NCon Kolivas <kernel@kolivas.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      bd96b9eb
    • C
      [PATCH] More page migration: use migration entries for file pages · 04e62a29
      由 Christoph Lameter 提交于 
      This implements the use of migration entries to preserve ptes of file backed
pages during migration.  Processes can therefore be migrated back and forth
without loosing their connection to pagecache pages.

Note that we implement the migration entries only for linear mappings.
Nonlinear mappings still require the unmapping of the ptes for migration.

And another writepage() ugliness shows up.  writepage() can drop the page
lock.  Therefore we have to remove migration ptes before calling writepages()
in order to avoid having migration entries point to unlocked pages.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      04e62a29
    • C
      [PATCH] Swapless page migration: add R/W migration entries · 0697212a
      由 Christoph Lameter 提交于 
      Implement read/write migration ptes

We take the upper two swapfiles for the two types of migration ptes and define
a series of macros in swapops.h.

The VM is modified to handle the migration entries.  migration entries can
only be encountered when the page they are pointing to is locked.  This limits
the number of places one has to fix.  We also check in copy_pte_range and in
mprotect_pte_range() for migration ptes.

We check for migration ptes in do_swap_cache and call a function that will
then wait on the page lock.  This allows us to effectively stop all accesses
to apge.

Migration entries are created by try_to_unmap if called for migration and
removed by local functions in migrate.c

From: Hugh Dickins <hugh@veritas.com>

  Several times while testing swapless page migration (I've no NUMA, just
  hacking it up to migrate recklessly while running load), I've hit the
  BUG_ON(!PageLocked(p)) in migration_entry_to_page.

  This comes from an orphaned migration entry, unrelated to the current
  correctly locked migration, but hit by remove_anon_migration_ptes as it
  checks an address in each vma of the anon_vma list.

  Such an orphan may be left behind if an earlier migration raced with fork:
  copy_one_pte can duplicate a migration entry from parent to child, after
  remove_anon_migration_ptes has checked the child vma, but before it has
  removed it from the parent vma.  (If the process were later to fault on this
  orphaned entry, it would hit the same BUG from migration_entry_wait.)

  This could be fixed by locking anon_vma in copy_one_pte, but we'd rather
  not.  There's no such problem with file pages, because vma_prio_tree_add
  adds child vma after parent vma, and the page table locking at each end is
  enough to serialize.  Follow that example with anon_vma: add new vmas to the
  tail instead of the head.

  (There's no corresponding problem when inserting migration entries,
  because a missed pte will leave the page count and mapcount high, which is
  allowed for.  And there's no corresponding problem when migrating via swap,
  because a leftover swap entry will be correctly faulted.  But the swapless
  method has no refcounting of its entries.)

From: Ingo Molnar <mingo@elte.hu>

  pte_unmap_unlock() takes the pte pointer as an argument.

From: Hugh Dickins <hugh@veritas.com>

  Several times while testing swapless page migration, gcc has tried to exec
  a pointer instead of a string: smells like COW mappings are not being
  properly write-protected on fork.

  The protection in copy_one_pte looks very convincing, until at last you
  realize that the second arg to make_migration_entry is a boolean "write",
  and SWP_MIGRATION_READ is 30.

  Anyway, it's better done like in change_pte_range, using
  is_write_migration_entry and make_migration_entry_read.

From: Hugh Dickins <hugh@veritas.com>

  Remove unnecessary obfuscation from sys_swapon's range check on swap type,
  which blew up causing memory corruption once swapless migration made
  MAX_SWAPFILES no longer 2 ^ MAX_SWAPFILES_SHIFT.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NChristoph Lameter <clameter@engr.sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
From: Hugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      0697212a
    • A
      [PATCH] reserve space for swap label · e8f03d02
      由 Andreas Dilger 提交于 
      Reserve space in the swap disk header for a LABEL and UUID to be specified.
 This has been possible with util-linux-2.12b (via e2fsprogs 1.36
libblkid), and is used by at least FC3 and later.  The kernel doesn't
really care about this, but the space shouldn't accidentally be used by
something else either.

Also make the on-disk structures be fixed-size types, instead of "int",
though I don't know of any architecture in use where an "int" isn't the
same size as a "__u32" (all current kernel arches have it as "unsigned
int").
Signed-off-by: NAndreas Dilger <adilger@shaw.ca>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      e8f03d02
  7. 16 5月, 2006 1 次提交
  9. 26 4月, 2006 1 次提交
  11. 11 4月, 2006 1 次提交
    • H
      [PATCH] overcommit: add calculate_totalreserve_pages() · cb45b0e9
      由 Hideo AOKI 提交于 
      These patches are an enhancement of OVERCOMMIT_GUESS algorithm in
__vm_enough_memory().

- why the kernel needed patching

  When the kernel can't allocate anonymous pages in practice, currnet
  OVERCOMMIT_GUESS could return success. This implementation might be
  the cause of oom kill in memory pressure situation.

  If the Linux runs with page reservation features like
  /proc/sys/vm/lowmem_reserve_ratio and without swap region, I think
  the oom kill occurs easily.

- the overall design approach in the patch

  When the OVERCOMMET_GUESS algorithm calculates number of free pages,
  the reserved free pages are regarded as non-free pages.

  This change helps to avoid the pitfall that the number of free pages
  become less than the number which the kernel tries to keep free.

- testing results

  I tested the patches using my test kernel module.

  If the patches aren't applied to the kernel, __vm_enough_memory()
  returns success in the situation but autual page allocation is
  failed.

  On the other hand, if the patches are applied to the kernel, memory
  allocation failure is avoided since __vm_enough_memory() returns
  failure in the situation.

  I checked that on i386 SMP 16GB memory machine. I haven't tested on
  nommu environment currently.

This patch adds totalreserve_pages for __vm_enough_memory().

Calculate_totalreserve_pages() checks maximum lowmem_reserve pages and
pages_high in each zone. Finally, the function stores the sum of each
zone to totalreserve_pages.

The totalreserve_pages is calculated when the VM is initilized.
And the variable is updated when /proc/sys/vm/lowmem_reserve_raito
or /proc/sys/vm/min_free_kbytes are changed.
Signed-off-by: NHideo Aoki <haoki@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      cb45b0e9
  13. 23 3月, 2006 1 次提交
  15. 22 3月, 2006 2 次提交
  17. 21 2月, 2006 1 次提交
    • C
      [PATCH] Terminate process that fails on a constrained allocation · 9b0f8b04
      由 Christoph Lameter 提交于 
      Some allocations are restricted to a limited set of nodes (due to memory
policies or cpuset constraints).  If the page allocator is not able to find
enough memory then that does not mean that overall system memory is low.

In particular going postal and more or less randomly shooting at processes
is not likely going to help the situation but may just lead to suicide (the
whole system coming down).

It is better to signal to the process that no memory exists given the
constraints that the process (or the configuration of the process) has
placed on the allocation behavior.  The process may be killed but then the
sysadmin or developer can investigate the situation.  The solution is
similar to what we do when running out of hugepages.

This patch adds a check before we kill processes.  At that point
performance considerations do not matter much so we just scan the zonelist
and reconstruct a list of nodes.  If the list of nodes does not contain all
online nodes then this is a constrained allocation and we should kill the
current process.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      9b0f8b04
  19. 02 2月, 2006 4 次提交
  21. 19 1月, 2006 2 次提交
  23. 15 1月, 2006 1 次提交
  25. 09 1月, 2006 6 次提交
    • C
      [PATCH] SwapMig: Extend parameters for migrate_pages() · d4984711
      由 Christoph Lameter 提交于 
      Extend the parameters of migrate_pages() to allow the caller control over the
fate of successfully migrated or impossible to migrate pages.

Swap migration and direct migration will have the same interface after this
patch so that patches can be independently applied to the policy layer and the
core migration code.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      d4984711
    • C
      [PATCH] SwapMig: add_to_swap() avoid atomic allocations · 1480a540
      由 Christoph Lameter 提交于 
      Add gfp_mask to add_to_swap

add_to_swap does allocations with GFP_ATOMIC in order not to interfere with
swapping.  During migration we may have use add_to_swap extensively which may
lead to out of memory errors.

This patch makes add_to_swap take a parameter that specifies the gfp mask.
The page migration code can then make add_to_swap use GFP_KERNEL.
Signed-off-by: NHirokazu Takahashi <taka@valinux.co.jp>
Signed-off-by: NDave Hansen <haveblue@us.ibm.com>
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      1480a540
    • C
      [PATCH] SwapMig: CONFIG_MIGRATION fixes · 8419c318
      由 Christoph Lameter 提交于 
      Move move_to_lru, putback_lru_pages and isolate_lru in section surrounded by
CONFIG_MIGRATION saving some codesize for single processor kernels.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      8419c318
    • C
      [PATCH] Swap Migration V5: Add CONFIG_MIGRATION for page migration support · 7cbe34cf
      由 Christoph Lameter 提交于 
      Include page migration if the system is NUMA or having a memory model that
allows distinct areas of memory (SPARSEMEM, DISCONTIGMEM).

And:
- Only include lru_add_drain_per_cpu if building for an SMP system.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      7cbe34cf
    • C
      [PATCH] Swap Migration V5: migrate_pages() function · 49d2e9cc
      由 Christoph Lameter 提交于 
      This adds the basic page migration function with a minimal implementation that
only allows the eviction of pages to swap space.

Page eviction and migration may be useful to migrate pages, to suspend
programs or for remapping single pages (useful for faulty pages or pages with
soft ECC failures)

The process is as follows:

The function wanting to migrate pages must first build a list of pages to be
migrated or evicted and take them off the lru lists via isolate_lru_page().
isolate_lru_page determines that a page is freeable based on the LRU bit set.

Then the actual migration or swapout can happen by calling migrate_pages().

migrate_pages does its best to migrate or swapout the pages and does multiple
passes over the list.  Some pages may only be swappable if they are not dirty.
 migrate_pages may start writing out dirty pages in the initial passes over
the pages.  However, migrate_pages may not be able to migrate or evict all
pages for a variety of reasons.

The remaining pages may be returned to the LRU lists using putback_lru_pages().

Changelog V4->V5:
- Use the lru caches to return pages to the LRU

Changelog V3->V4:
- Restructure code so that applying patches to support full migration does
  require minimal changes. Rename swapout_pages() to migrate_pages().

Changelog V2->V3:
- Extract common code from shrink_list() and swapout_pages()
Signed-off-by: NMike Kravetz <kravetz@us.ibm.com>
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Cc: "Michael Kerrisk" <mtk-manpages@gmx.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      49d2e9cc
    • C
      [PATCH] Swap Migration V5: LRU operations · 21eac81f
      由 Christoph Lameter 提交于 
      This is the start of the `swap migration' patch series.

Swap migration allows the moving of the physical location of pages between
nodes in a numa system while the process is running.  This means that the
virtual addresses that the process sees do not change.  However, the system
rearranges the physical location of those pages.

The main intent of page migration patches here is to reduce the latency of
memory access by moving pages near to the processor where the process
accessing that memory is running.

The patchset allows a process to manually relocate the node on which its
pages are located through the MF_MOVE and MF_MOVE_ALL options while
setting a new memory policy.

The pages of process can also be relocated from another process using the
sys_migrate_pages() function call.  Requires CAP_SYS_ADMIN.  The migrate_pages
function call takes two sets of nodes and moves pages of a process that are
located on the from nodes to the destination nodes.

Manual migration is very useful if for example the scheduler has relocated a
process to a processor on a distant node.  A batch scheduler or an
administrator can detect the situation and move the pages of the process
nearer to the new processor.

sys_migrate_pages() could be used on non-numa machines as well, to force all
of a particualr process's pages out to swap, if someone thinks that's useful.

Larger installations usually partition the system using cpusets into sections
of nodes.  Paul has equipped cpusets with the ability to move pages when a
task is moved to another cpuset.  This allows automatic control over locality
of a process.  If a task is moved to a new cpuset then also all its pages are
moved with it so that the performance of the process does not sink
dramatically (as is the case today).

Swap migration works by simply evicting the page.  The pages must be faulted
back in.  The pages are then typically reallocated by the system near the node
where the process is executing.

For swap migration the destination of the move is controlled by the allocation
policy.  Cpusets set the allocation policy before calling sys_migrate_pages()
in order to move the pages as intended.

No allocation policy changes are performed for sys_migrate_pages().  This
means that the pages may not faulted in to the specified nodes if no
allocation policy was set by other means.  The pages will just end up near the
node where the fault occurred.

There's another patch series in the pipeline which implements "direct
migration".

The direct migration patchset extends the migration functionality to avoid
going through swap.  The destination node of the relation is controllable
during the actual moving of pages.  The crutch of using the allocation policy
to relocate is not necessary and the pages are moved directly to the target.
Its also faster since swap is not used.

And sys_migrate_pages() can then move pages directly to the specified node.
Implement functions to isolate pages from the LRU and put them back later.

This patch:

An earlier implementation was provided by Hirokazu Takahashi
<taka@valinux.co.jp> and IWAMOTO Toshihiro <iwamoto@valinux.co.jp> for the
memory hotplug project.

From: Magnus

This breaks out isolate_lru_page() and putpack_lru_page().  Needed for swap
migration.
Signed-off-by: NMagnus Damm <magnus.damm@gmail.com>
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      21eac81f
  27. 07 1月, 2006 2 次提交
  29. 29 11月, 2005 1 次提交
    • R
      [PATCH] temporarily disable swap token on memory pressure · f7b7fd8f
      由 Rik van Riel 提交于 
      Some users (hi Zwane) have seen a problem when running a workload that
eats nearly all of physical memory - th system does an OOM kill, even
when there is still a lot of swap free.

The problem appears to be a very big task that is holding the swap
token, and the VM has a very hard time finding any other page in the
system that is swappable.

Instead of ignoring the swap token when sc->priority reaches 0, we could
simply take the swap token away from the memory hog and make sure we
don't give it back to the memory hog for a few seconds.

This patch resolves the problem Zwane ran into.
Signed-off-by: NRik van Riel <riel@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      f7b7fd8f
  31. 28 10月, 2005 1 次提交
  33. 09 10月, 2005 1 次提交
  35. 05 9月, 2005 5 次提交
    • H
      [PATCH] swap: swap_lock replace list+device · 5d337b91
      由 Hugh Dickins 提交于 
      The idea of a swap_device_lock per device, and a swap_list_lock over them all,
is appealing; but in practice almost every holder of swap_device_lock must
already hold swap_list_lock, which defeats the purpose of the split.

The only exceptions have been swap_duplicate, valid_swaphandles and an
untrodden path in try_to_unuse (plus a few places added in this series).
valid_swaphandles doesn't show up high in profiles, but swap_duplicate does
demand attention.  However, with the hold time in get_swap_pages so much
reduced, I've not yet found a load and set of swap device priorities to show
even swap_duplicate benefitting from the split.  Certainly the split is mere
overhead in the common case of a single swap device.

So, replace swap_list_lock and swap_device_lock by spinlock_t swap_lock
(generally we seem to prefer an _ in the name, and not hide in a macro).

If someone can show a regression in swap_duplicate, then probably we should
add a hashlock for the swap_map entries alone (shorts being anatomic), so as
to help the case of the single swap device too.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      5d337b91
    • H
      [PATCH] swap: scan_swap_map drop swap_device_lock · 52b7efdb
      由 Hugh Dickins 提交于 
      get_swap_page has often shown up on latency traces, doing lengthy scans while
holding two spinlocks.  swap_list_lock is already dropped, now scan_swap_map
drop swap_device_lock before scanning the swap_map.

While scanning for an empty cluster, don't worry that racing tasks may
allocate what was free and free what was allocated; but when allocating an
entry, check it's still free after retaking the lock.  Avoid dropping the lock
in the expected common path.  No barriers beyond the locks, just let the
cookie crumble; highest_bit limit is volatile, but benign.

Guard against swapoff: must check SWP_WRITEOK before allocating, must raise
SWP_SCANNING reference count while in scan_swap_map, swapoff wait for that to
fall - just use schedule_timeout, we don't want to burden scan_swap_map
itself, and it's very unlikely that anyone can really still be in
scan_swap_map once swapoff gets this far.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      52b7efdb
    • H
      [PATCH] swap: swap unsigned int consistency · 6eb396dc
      由 Hugh Dickins 提交于 
      The swap header's unsigned int last_page determines the range of swap pages,
but swap_info has been using int or unsigned long in some cases: use unsigned
int throughout (except, in several places a local unsigned long is useful to
avoid overflows when adding).
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NJens Axboe <axboe@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      6eb396dc
    • H
      [PATCH] swap: show span of swap extents · 53092a74
      由 Hugh Dickins 提交于 
      The "Adding %dk swap" message shows the number of swap extents, as a guide to
how fragmented the swapfile may be.  But a useful further guide is what total
extent they span across (sometimes scarily large).

And there's no need to keep nr_extents in swap_info: it's unused after the
initial message, so save a little space by keeping it on stack.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      53092a74
    • H
      [PATCH] swap: swap extent list is ordered · 11d31886
      由 Hugh Dickins 提交于 
      There are several comments that swap's extent_list.prev points to the lowest
extent: that's not so, it's extent_list.next which points to it, as you'd
expect.  And a couple of loops in add_swap_extent which go all the way through
the list, when they should just add to the other end.

Fix those up, and let map_swap_page search the list forwards: profiles shows
it to be twice as quick that way - because prefetch works better on how the
structs are typically kmalloc'ed?  or because usually more is written to than
read from swap, and swap is allocated ascendingly?
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      11d31886
  37. 08 8月, 2005 1 次提交
  39. 13 7月, 2005 1 次提交
  41. 08 7月, 2005 1 次提交