linux-stable.git/include/linux/swap.h, branch linux-2.6.14.y

[PATCH] gfp flags annotations - part 1

2005-10-08T22:00:57+00:00

 - added typedef unsigned int __nocast gfp_t;

 - replaced __nocast uses for gfp flags with gfp_t - it gives exactly
   the same warnings as far as sparse is concerned, doesn't change
   generated code (from gcc point of view we replaced unsigned int with
   typedef) and documents what's going on far better.

Signed-off-by: Al Viro 
Signed-off-by: Linus Torvalds

[PATCH] swap: swap_lock replace list+device

2005-09-05T07:05:42+00:00

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: Hugh Dickins 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] swap: scan_swap_map drop swap_device_lock

2005-09-05T07:05:41+00:00

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: Hugh Dickins 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] swap: swap unsigned int consistency

2005-09-05T07:05:41+00:00

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: Hugh Dickins 
Signed-off-by: Jens Axboe 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] swap: show span of swap extents

2005-09-05T07:05:40+00:00

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: Hugh Dickins 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] swap: swap extent list is ordered

2005-09-05T07:05:40+00:00

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: Hugh Dickins 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] remove linux/pagemap.h from linux/swap.h

2005-08-07T17:00:38+00:00

sparc can not include linux/pagemap.h because of the following circular
dependency:

asm-sparc/pgtable include linux/swap.h
linux/swap.h include now linux/pagemap.h
linux/pagemap.h include linux/mm.h
linux/mm.h include asm/pgtable.h

It needs to have the swp_entry_t type fully visible in pgtable.h,
we can't work around this using macros.

Signed-off-by: Olaf Hering 
Cc: William Lee Irwin III 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] tlb.h warning fix

2005-07-12T23:01:02+00:00

free_pages_and_swap_cache() and free_page_and_swap_cache() use release_pages()
and page_cache_release() respectively, so make sure that we have the
declarations in scope.

Cc: Olaf Hering 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] print order information when OOM killing

2005-07-08T01:23:35+00:00

Dump the current allocation order when OOM killing.

Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] vm: try_to_free_pages unused argument

2005-06-22T01:46:17+00:00

try_to_free_pages accepts a third argument, order, but hasn't used it since
before 2.6.0.  The following patch removes the argument and updates all the
calls to try_to_free_pages.

Signed-off-by: Darren Hart 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds