05 Aug, 2008
1 commit
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Converting page lock to new locking bitops requires a change of page flag
operation naming, so we might as well convert it to something nicer
(!TestSetPageLocked_Lock => trylock_page, SetPageLocked => set_page_locked).This also facilitates lockdeping of page lock.
Signed-off-by: Nick Piggin
Acked-by: KOSAKI Motohiro
Acked-by: Peter Zijlstra
Acked-by: Andrew Morton
Acked-by: Benjamin Herrenschmidt
Signed-off-by: Linus Torvalds
31 Jul, 2008
1 commit
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Signed-off-by: Fernando Luis Vazquez Cao
Cc: Hugh Dickins
Cc: Nick Piggin
Cc: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Jul, 2008
2 commits
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This patch makes the following needlessly global code static:
- swap_lock
- nr_swapfiles
- struct swap_listSigned-off-by: Adrian Bunk
Reviewed-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
mapping->tree_lock has no read lockers. convert the lock from an rwlock
to a spinlock.Signed-off-by: Nick Piggin
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: Hugh Dickins
Cc: "Paul E. McKenney"
Reviewed-by: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 Jul, 2008
1 commit
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Vegard Nossum has noticed the ever-decreasing negative priority in a
swapon /swapoff loop, which eventually would misprioritize when int wraps
positive. Not worth spending much code on, but probably better fixed.It's easy to handle the swapping on and off of just one area, but there's
not much point if a pair or more still misbehave. To handle the general
case, swapoff should compact negative priorities, keeping them always from
-1 to -MAX_SWAPFILES. That's a change, but should cause no regression,
since these negative (unspecified) priorities are disjoint from the the
positive specified priorities 0 to 32767.One small functional difference, which seems appropriate: when swapoff
fails to free all swap from a negative priority area, that area is now
reinserted at lowest priority, rather than at its original priority.In moving down swapon's setting of priority, I notice that an area is
visible to /proc/swaps when it has swap_map set, yet that was being set
before all the visible fields were properly filled in: corrected.Signed-off-by: Hugh Dickins
Reviewed-by: KOSAKI Motohiro
Reported-by: Vegard Nossum
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Apr, 2008
1 commit
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Use proc_create() to make sure that ->proc_fops be setup before gluing PDE to
main tree.Signed-off-by: Denis V. Lunev
Cc: Alexey Dobriyan
Cc: "Eric W. Biederman"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
28 Apr, 2008
1 commit
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When checking for the swap header try byteswapping the endianess dependent
fields to allow the swap partition to be shared between big & little endian
systems.Signed-off-by: Chris Dearman
Signed-off-by: Ralf Baechle
Acked-by: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
15 Feb, 2008
1 commit
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seq_path() is always called with a dentry and a vfsmount from a struct path.
Make seq_path() take it directly as an argument.Signed-off-by: Jan Blunck
Cc: Christoph Hellwig
Cc: Al Viro
Cc: "J. Bruce Fields"
Cc: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 Feb, 2008
4 commits
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This patch reinstates the "swapoff: scan ptes preemptibly" mod we started
with: in due course it should be rendered down into the earlier patches,
leaving us with a more straightforward mem_cgroup_charge mod to unuse_pte,
allocating with GFP_KERNEL while holding no spinlock and no atomic kmap.Signed-off-by: Hugh Dickins
Cc: Pavel Emelianov
Acked-by: Balbir Singh
Cc: Paul Menage
Cc: Peter Zijlstra
Cc: "Eric W. Biederman"
Cc: Nick Piggin
Cc: Kirill Korotaev
Cc: Herbert Poetzl
Cc: David Rientjes
Cc: Vaidyanathan Srinivasan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Nick Piggin pointed out that swap cache and page cache addition routines
could be called from non GFP_KERNEL contexts. This patch makes the
charging routine aware of the gfp context. Charging might fail if the
cgroup is over it's limit, in which case a suitable error is returned.This patch was tested on a Powerpc box. I am still looking at being able
to test the path, through which allocations happen in non GFP_KERNEL
contexts.[kamezawa.hiroyu@jp.fujitsu.com: problem with ZONE_MOVABLE]
Signed-off-by: Balbir Singh
Cc: Pavel Emelianov
Cc: Paul Menage
Cc: Peter Zijlstra
Cc: "Eric W. Biederman"
Cc: Nick Piggin
Cc: Kirill Korotaev
Cc: Herbert Poetzl
Cc: David Rientjes
Cc: Vaidyanathan Srinivasan
Signed-off-by: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add the accounting hooks. The accounting is carried out for RSS and Page
Cache (unmapped) pages. There is now a common limit and accounting for both.
The RSS accounting is accounted at page_add_*_rmap() and page_remove_rmap()
time. Page cache is accounted at add_to_page_cache(),
__delete_from_page_cache(). Swap cache is also accounted for.Each page's page_cgroup is protected with the last bit of the
page_cgroup pointer, this makes handling of race conditions involving
simultaneous mappings of a page easier. A reference count is kept in the
page_cgroup to deal with cases where a page might be unmapped from the RSS
of all tasks, but still lives in the page cache.Credits go to Vaidyanathan Srinivasan for helping with reference counting work
of the page cgroup. Almost all of the page cache accounting code has help
from Vaidyanathan Srinivasan.[hugh@veritas.com: fix swapoff breakage]
[akpm@linux-foundation.org: fix locking]
Signed-off-by: Vaidyanathan Srinivasan
Signed-off-by: Balbir Singh
Cc: Pavel Emelianov
Cc: Paul Menage
Cc: Peter Zijlstra
Cc: "Eric W. Biederman"
Cc: Nick Piggin
Cc: Kirill Korotaev
Cc: Herbert Poetzl
Cc: David Rientjes
Cc:
Signed-off-by: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch precisely reverts the "swapoff: scan ptes preemptibly" patch
just presented. It's a temporary measure to allow existing memory
controller patches to apply without rejects: in due course they should be
rendered down into one sensible patch, and this reversion disappear.Signed-off-by: Hugh Dickins
Cc: Balbir Singh
Cc: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Feb, 2008
4 commits
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There are a couple of reasons (patches follow) why it would be good to open a
window for sleep in shmem_unuse_inode, between its search for a matching swap
entry, and its handling of the entry found.shmem_unuse_inode must then use igrab to hold the inode against deletion in
that window, and its corresponding iput might result in deletion: so it had
better unlock_page before the iput, and might as well release the page too.Nor is there any need to hold on to shmem_swaplist_mutex once we know we'll
leave the loop. So this unwinding moves from try_to_unuse and shmem_unuse
into shmem_unuse_inode, in the case when it finds a match.Let try_to_unuse break on error in the shmem_unuse case, as it does in the
unuse_mm case: though at this point in the series, no error to break on.Signed-off-by: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Provided that CONFIG_HIGHPTE is not set, unuse_pte_range can reduce latency
in swapoff by scanning the page table preemptibly: so long as unuse_pte is
careful to recheck that entry under pte lock.(To tell the truth, this patch was not inspired by any cries for lower
latency here: rather, this restructuring permits a future memory controller
patch to allocate with GFP_KERNEL in unuse_pte, where before it could not.
But it would be wrong to tuck this change away inside a memcgroup patch.)Signed-off-by: Hugh Dickins
Acked-by: Balbir Singh
Tested-by: Balbir Singh
Cc: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
valid_swaphandles is supposed to do a quick pass over the swap map entries
neigbouring the entry which swapin_readahead is targetting, to determine for
it a range worth reading all together. But since it always starts its search
from the beginning of the swap "cluster", a reject (free entry) there
immediately curtails the readaround, and every swapin_readahead from that
cluster is for just a single page. Instead scan forwards and backwards around
the target entry.Use better names for some variables: a swap_info pointer is usually called
"si" not "swapdev". And at the end, if only the target page should be read,
return count of 0 to disable readaround, to avoid the unnecessarily repeated
call to read_swap_cache_async.Signed-off-by: Hugh Dickins
Acked-by: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Building in a filesystem on a loop device on a tmpfs file can hang when
swapping, the loop thread caught in that infamous throttle_vm_writeout.In theory this is a long standing problem, which I've either never seen in
practice, or long ago suppressed the recollection, after discounting my load
and my tmpfs size as unrealistically high. But now, with the new aops, it has
become easy to hang on one machine.Loop used to grab_cache_page before the old prepare_write to tmpfs, which
seems to have been enough to free up some memory for any swapin needed; but
the new write_begin lets tmpfs find or allocate the page (much nicer, since
grab_cache_page missed tmpfs pages in swapcache).When allocating a fresh page, tmpfs respects loop's mapping_gfp_mask, which
has __GFP_IO|__GFP_FS stripped off, and throttle_vm_writeout is designed to
break out when __GFP_IO or GFP_FS is unset; but when tmfps swaps in,
read_swap_cache_async allocates with GFP_HIGHUSER_MOVABLE regardless of the
mapping_gfp_mask - hence the hang.So, pass gfp_mask down the line from shmem_getpage to shmem_swapin to
swapin_readahead to read_swap_cache_async to add_to_swap_cache.Signed-off-by: Hugh Dickins
Acked-by: Rik van Riel
Acked-by: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Jul, 2007
1 commit
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Replace CONFIG_SOFTWARE_SUSPEND with CONFIG_HIBERNATION to avoid
confusion (among other things, with CONFIG_SUSPEND introduced in the
next patch).Signed-off-by: Rafael J. Wysocki
Signed-off-by: Linus Torvalds
17 Jul, 2007
1 commit
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Fix the shrink_list name on some files under mm/ directory.
Signed-off-by: Anderson Briglia
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 May, 2007
1 commit
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Ensure pages are uptodate after returning from read_cache_page, which allows
us to cut out most of the filesystem-internal PageUptodate calls.I didn't have a great look down the call chains, but this appears to fixes 7
possible use-before uptodate in hfs, 2 in hfsplus, 1 in jfs, a few in
ecryptfs, 1 in jffs2, and a possible cleared data overwritten with readpage in
block2mtd. All depending on whether the filler is async and/or can return
with a !uptodate page.Signed-off-by: Nick Piggin
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Jan, 2007
1 commit
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In the kernels later than 2.6.19 there is a regression that makes swsusp
fail if the resume device is not explicitly specified.It can be fixed by adding an additional parameter to
mm/swapfile.c:swap_type_of() allowing us to pass the (struct block_device
*) corresponding to the first available swap back to the caller.Signed-off-by: Rafael J. Wysocki
Acked-by: Pavel Machek
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Dec, 2006
1 commit
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Change all the uses of f_{dentry,vfsmnt} to f_path.{dentry,mnt} in linux/mm/.
Signed-off-by: Josef "Jeff" Sipek
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 Dec, 2006
5 commits
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- move some file_operations structs into the .rodata section
- move static strings from policy_types[] array into the .rodata section
- fix generic seq_operations usages, so that those structs may be defined
as "const" as well[akpm@osdl.org: couple of fixes]
Signed-off-by: Helge Deller
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Make swsusp use block device offsets instead of swap offsets to identify swap
locations and make it use the same code paths for writing as well as for
reading data.This allows us to use the same code for handling swap files and swap
partitions and to simplify the code, eg. by dropping rw_swap_page_sync().Signed-off-by: Rafael J. Wysocki
Cc: Pavel Machek
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The Linux kernel handles swap files almost in the same way as it handles swap
partitions and there are only two differences between these two types of swap
areas:(1) swap files need not be contiguous,
(2) the header of a swap file is not in the first block of the partition
that holds it. From the swsusp's point of view (1) is not a problem,
because it is already taken care of by the swap-handling code, but (2) has
to be taken into consideration.In principle the location of a swap file's header may be determined with the
help of appropriate filesystem driver. Unfortunately, however, it requires
the filesystem holding the swap file to be mounted, and if this filesystem is
journaled, it cannot be mounted during a resume from disk. For this reason we
need some other means by which swap areas can be identified.For example, to identify a swap area we can use the partition that holds the
area and the offset from the beginning of this partition at which the swap
header is located.The following patch allows swsusp to identify swap areas this way. It changes
swap_type_of() so that it takes an additional argument representing an offset
of the swap header within the partition represented by its first argument.Signed-off-by: Rafael J. Wysocki
Acked-by: Pavel Machek
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The fsfuzzer found this; with a corrupt small swapfile that claims to have
many pages:[root]# file swap.741.img
swap.741.img: Linux/i386 swap file (new style) 1 (4K pages) size 1040191487 pages
[root]# ls -l swap.741.img
-rw-r--r-- 1 root root 16777216 Nov 22 05:18 swap.741.imgsys_swapon() will try to vmalloc all those pages, and -then- check to see if
the file is actually that large:if (!(p->swap_map = vmalloc(maxpages * sizeof(short)))) {
if (swapfilesize && maxpages > swapfilesize) {
printk(KERN_WARNING
"Swap area shorter than signature indicates\n");It seems to me that it would make more sense to move this test up before
the vmalloc, with the other checks, to avoid the OOM-killer in this
situation...Signed-off-by: Eric Sandeen
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
It would be possible for /proc/swaps to not always print out the header:
swapon /dev/hdc2
swapon /dev/hde2
swapoff /dev/hdc2At this point /proc/swaps would not have a header.
Signed-off-by: Suleiman Souhlal
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Sep, 2006
1 commit
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akpm draws my attention to the fact that sysctl(VM_PAGE_CLUSTER) might
conceivably change page_cluster to 0 while valid_swaphandles() is in the
middle of using it, leading to an embarrassingly long loop: take a local
snapshot of page_cluster and work with that.Signed-off-by: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
28 Aug, 2006
1 commit
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There is a bug in mm/swapfile.c#swap_type_of() that makes swsusp only be
able to use the first active swap partition as the resume device. Fix it.Signed-off-by: Rafael J. Wysocki
Cc: Hugh Dickins
Acked-by: Pavel Machek
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Jul, 2006
1 commit
-
Signed-off-by: Jörn Engel
Signed-off-by: Adrian Bunk
23 Jun, 2006
5 commits
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Add read_mapping_page() which is used for callers that pass
mapping->a_ops->readpage as the filler for read_cache_page. This removes
some duplication from filesystem code.Signed-off-by: Pekka Enberg
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Now that we have atomic_inc_not_zero, it's more elegant for try_to_unuse to
use that on mm_users: doesn't actually matter at present, but safer to be
sure that once mm_users has gone to 0, nothing raises it for an instant.Signed-off-by: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Rip the page migration logic out.
Remove all code that has to do with swapping during page migration.
This also guts the ability to migrate pages to swap. No one used that so lets
let it go for good.Page migration should be a bit broken after this patch.
Signed-off-by: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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.cFrom: Hugh Dickins
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
pte_unmap_unlock() takes the pte pointer as an argument.
From: Hugh Dickins
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
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: Hugh Dickins
Acked-by: Martin Schwidefsky
Signed-off-by: Hugh Dickins
Signed-off-by: Christoph Lameter
Signed-off-by: Ingo Molnar
From: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Remove two unnecessary PageSwapCache checks. The page refcount is raised
and therefore page migration cannot occur in both functions.Signed-off-by: Christoph Lameter
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Apr, 2006
1 commit
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find_trylock_page() is an odd interface in that it doesn't take a reference
like the others. Now that XFS no longer uses it, and its last remaining
caller actually wants an elevated refcount, opencode that callsite and
schedule find_trylock_page() for removal.Signed-off-by: Nick Piggin
Acked-by: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
23 Mar, 2006
2 commits
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This patch introduces a user space interface for swsusp.
The interface is based on a special character device, called the snapshot
device, that allows user space processes to perform suspend and resume-related
operations with the help of some ioctls and the read()/write() functions.
Additionally it allows these processes to allocate free swap pages from a
selected swap partition, called the resume partition, so that they know which
sectors of the resume partition are available to them.The interface uses the same low-level system memory snapshot-handling
functions that are used by the built-it swap-writing/reading code of swsusp.The interface documentation is included in the patch.
The patch assumes that the major and minor numbers of the snapshot device will
be 10 (ie. misc device) and 231, the registration of which has already been
requested.Signed-off-by: Rafael J. Wysocki
Acked-by: Pavel Machek
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Introduce the low level interface that can be used for handling the
snapshot of the system memory by the in-kernel swap-writing/reading code of
swsusp and the userland interface code (to be introduced shortly).Also change the way in which swsusp records the allocated swap pages and,
consequently, simplifies the in-kernel swap-writing/reading code (this is
necessary for the userland interface too). To this end, it introduces two
helper functions in mm/swapfile.c, so that the swsusp code does not refer
directly to the swap internals.Signed-off-by: Rafael J. Wysocki
Acked-by: Pavel Machek
Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 Mar, 2006
1 commit
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When we've allocated SWAPFILE_CLUSTER pages, ->cluster_next should be the
first index of swap cluster. But current code probably sets it wrong offset.Signed-off-by: Akinobu Mita
Acked-by: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Feb, 2006
2 commits
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Add remove_from_swap
remove_from_swap() allows the restoration of the pte entries that existed
before page migration occurred for anonymous pages by walking the reverse
maps. This reduces swap use and establishes regular pte's without the need
for page faults.Signed-off-by: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Check for PageSwapCache after looking up and locking a swap page.
The page migration code may change a swap pte to point to a different page
under lock_page().If that happens then the vm must retry the lookup operation in the swap space
to find the correct page number. There are a couple of locations in the VM
where a lock_page() is done on a swap page. In these locations we need to
check afterwards if the page was migrated. If the page was migrated then the
old page that was looked up before was freed and no longer has the
PageSwapCache bit set.Signed-off-by: Hirokazu Takahashi
Signed-off-by: Dave Hansen
Signed-off-by: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds