25 Mar, 2011
4 commits
-
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
fs: simplify iget & friends
fs: pull inode->i_lock up out of writeback_single_inode
fs: rename inode_lock to inode_hash_lock
fs: move i_wb_list out from under inode_lock
fs: move i_sb_list out from under inode_lock
fs: remove inode_lock from iput_final and prune_icache
fs: Lock the inode LRU list separately
fs: factor inode disposal
fs: protect inode->i_state with inode->i_lock
autofs4: Do not potentially dereference NULL pointer returned by fget() in autofs_dev_ioctl_setpipefd()
autofs4 - remove autofs4_lock
autofs4 - fix d_manage() return on rcu-walk
autofs4 - fix autofs4_expire_indirect() traversal
autofs4 - fix dentry leak in autofs4_expire_direct()
autofs4 - reinstate last used update on access
vfs - check non-mountpoint dentry might block in __follow_mount_rcu() -
Protect the inode writeback list with a new global lock
inode_wb_list_lock and use it to protect the list manipulations and
traversals. This lock replaces the inode_lock as the inodes on the
list can be validity checked while holding the inode->i_lock and
hence the inode_lock is no longer needed to protect the list.Signed-off-by: Dave Chinner
Signed-off-by: Al Viro -
Protect inode state transitions and validity checks with the
inode->i_lock. This enables us to make inode state transitions
independently of the inode_lock and is the first step to peeling
away the inode_lock from the code.This requires that __iget() is done atomically with i_state checks
during list traversals so that we don't race with another thread
marking the inode I_FREEING between the state check and grabbing the
reference.Also remove the unlock_new_inode() memory barrier optimisation
required to avoid taking the inode_lock when clearing I_NEW.
Simplify the code by simply taking the inode->i_lock around the
state change and wakeup. Because the wakeup is no longer tricky,
remove the wake_up_inode() function and open code the wakeup where
necessary.Signed-off-by: Dave Chinner
Signed-off-by: Al Viro -
* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits)
Documentation/iostats.txt: bit-size reference etc.
cfq-iosched: removing unnecessary think time checking
cfq-iosched: Don't clear queue stats when preempt.
blk-throttle: Reset group slice when limits are changed
blk-cgroup: Only give unaccounted_time under debug
cfq-iosched: Don't set active queue in preempt
block: fix non-atomic access to genhd inflight structures
block: attempt to merge with existing requests on plug flush
block: NULL dereference on error path in __blkdev_get()
cfq-iosched: Don't update group weights when on service tree
fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away
block: Require subsystems to explicitly allocate bio_set integrity mempool
jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
fs: make fsync_buffers_list() plug
mm: make generic_writepages() use plugging
blk-cgroup: Add unaccounted time to timeslice_used.
block: fixup plugging stubs for !CONFIG_BLOCK
block: remove obsolete comments for blkdev_issue_zeroout.
blktrace: Use rq->cmd_flags directly in blk_add_trace_rq.
...Fix up conflicts in fs/{aio.c,super.c}
23 Mar, 2011
7 commits
-
Callers of find_get_pages(), or its wrapper pagevec_lookup() - notably
truncate_inode_pages_range() - stop looking further when it returns 0.But if an interrupt comes just after its radix_tree_gang_lookup_slot(),
especially if we have preemptible RCU enabled, isn't it conceivable that
all 14 pages returned could be removed from the page cache by
shrink_page_list(), before find_get_pages() gets to process them? So
causing it to return 0 although there may be plenty more pages beyond.Make find_get_pages() and find_get_pages_tag() check for this unlikely
case, and restart should it occur; but callers of find_get_pages_contig()
have no such expectation, it's okay for that to return 0 early.I have not seen this in practice, just worried by the possibility.
Signed-off-by: Hugh Dickins
Cc: Nick Piggin
Acked-by: Peter Zijlstra
Cc: Wu Fengguang
Cc: Salman Qazi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The radix_tree_deref_retry() case in find_get_pages() has a strange little
excrescence, not seen in the other gang lookups: it looks like the start
of an abandoned attempt to guarantee forward progress in a case that
cannot arise.ret should always be 0 here: if it isn't, then going back to restart will
leak references to pages already gotten. There used to be a comment
saying nr_found is necessarily 1 here: that's not quite true, but the
radix_tree_deref_retry() case is peculiar to the entry at index 0, when we
race with it being moved out of the radix_tree root or back.Remove the worrisome two lines, add a brief comment here and in
find_get_pages_contig() and find_get_pages_tag(), and a WARN_ON in
find_get_pages() should it ever be seen elsewhere than at 0.Signed-off-by: Hugh Dickins
Cc: Nick Piggin
Acked-by: Peter Zijlstra
Cc: Wu Fengguang
Cc: Salman Qazi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Now we renamed remove_from_page_cache with delete_from_page_cache. As
consistency of __remove_from_swap_cache and remove_from_swap_cache, we
change internal page cache handling function name, too.Signed-off-by: Minchan Kim
Cc: Christoph Hellwig
Acked-by: Hugh Dickins
Acked-by: Mel Gorman
Reviewed-by: KAMEZAWA Hiroyuki
Reviewed-by: Johannes Weiner
Reviewed-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Now delete_from_page_cache() replaces remove_from_page_cache(). So we
remove remove_from_page_cache so fs or something out of mainline will
notice it when compile time and can fix it.Signed-off-by: Minchan Kim
Cc: Christoph Hellwig
Acked-by: Hugh Dickins
Acked-by: Mel Gorman
Reviewed-by: KAMEZAWA Hiroyuki
Reviewed-by: Johannes Weiner
Reviewed-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Presently we increase the page refcount in add_to_page_cache() but don't
decrease it in remove_from_page_cache(). Such asymmetry adds confusion,
requiring that callers notice it and a comment explaining why they release
a page reference. It's not a good API.A long time ago, Hugh tried it (http://lkml.org/lkml/2004/10/24/140) but
gave up because reiser4's drop_page() had to unlock the page between
removing it from page cache and doing the page_cache_release(). But now
the situation is changed. I think at least things in current mainline
don't have any obstacles. The problem is for out-of-mainline filesystems
- if they have done such things as reiser4, this patch could be a problem
but they will discover this at compile time since we remove
remove_from_page_cache().This patch:
This function works as just wrapper remove_from_page_cache(). The
difference is that it decreases page references in itself. So caller have
to make sure it has a page reference before calling.This patch is ready for removing remove_from_page_cache().
Signed-off-by: Minchan Kim
Cc: Christoph Hellwig
Acked-by: Hugh Dickins
Acked-by: Mel Gorman
Reviewed-by: KAMEZAWA Hiroyuki
Reviewed-by: Johannes Weiner
Reviewed-by: KOSAKI Motohiro
Cc: Edward Shishkin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This function basically does:
remove_from_page_cache(old);
page_cache_release(old);
add_to_page_cache_locked(new);Except it does this atomically, so there's no possibility for the "add" to
fail because of a race.If memory cgroups are enabled, then the memory cgroup charge is also moved
from the old page to the new.This function is currently used by fuse to move pages into the page cache
on read, instead of copying the page contents.[minchan.kim@gmail.com: add freepage() hook to replace_page_cache_page()]
Signed-off-by: Miklos Szeredi
Acked-by: Rik van Riel
Acked-by: KAMEZAWA Hiroyuki
Cc: Mel Gorman
Signed-off-by: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
GUP user may want to try to acquire a reference to a page if it is already
in memory, but not if IO, to bring it in, is needed. For example KVM may
tell vcpu to schedule another guest process if current one is trying to
access swapped out page. Meanwhile, the page will be swapped in and the
guest process, that depends on it, will be able to run again.This patch adds FAULT_FLAG_RETRY_NOWAIT (suggested by Linus) and
FOLL_NOWAIT follow_page flags. FAULT_FLAG_RETRY_NOWAIT, when used in
conjunction with VM_FAULT_ALLOW_RETRY, indicates to handle_mm_fault that
it shouldn't drop mmap_sem and wait on a page, but return VM_FAULT_RETRY
instead.[akpm@linux-foundation.org: improve FOLL_NOWAIT comment]
Signed-off-by: Gleb Natapov
Cc: Linus Torvalds
Cc: Hugh Dickins
Acked-by: Rik van Riel
Cc: Michel Lespinasse
Cc: Avi Kivity
Cc: Marcelo Tosatti
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
10 Mar, 2011
2 commits
-
Signed-off-by: Jens Axboe
-
Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops->sync_page().Signed-off-by: Jens Axboe
14 Jan, 2011
3 commits
-
Running the annotated branch profiler on a box doing average work
(firefox, evolution, xchat, distcc farm), the likely() used in
grab_cache_page_write_begin() was incorrect most of the time:correct incorrect % Function File Line
------- --------- - -------- ---- ----
1924262 71332401 97 grab_cache_page_write_begin filemap.c 2206Adding a trace_printk() and running the function tracer limited to
just this function I can see:gconfd-2-2696 [000] 4467.268935: grab_cache_page_write_begin: page= (null) mapping=ffff8800676a9460 index=7
gconfd-2-2696 [000] 4467.268946: grab_cache_page_write_begin
Acked-by: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Temporary IO failures, eg. due to loss of both multipath paths, can
permanently leave the PageError bit set on a page, resulting in msync or
fsync returning -EIO over and over again, even if IO is now getting to the
disk correctly.We already clear the AS_ENOSPC and AS_IO bits in mapping->flags in the
filemap_fdatawait_range function. Also clearing the PageError bit on the
page allows subsequent msync or fsync calls on this file to return without
an error, if the subsequent IO succeeds.Unfortunately data written out in the msync or fsync call that returned
-EIO can still get lost, because the page dirty bit appears to not get
restored on IO error. However, the alternative could be potentially all
of memory filling up with uncleanable dirty pages, hanging the system, so
there is no nice choice here...Signed-off-by: Rik van Riel
Acked-by: Valerie Aurora
Acked-by: Jeff Layton
Cc: Theodore Ts'o
Acked-by: Jan Kara
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Testing ->mapping and ->index without a ref is not stable as the page
may have been reused at this point.Signed-off-by: Nick Piggin
Reviewed-by: Wu Fengguang
Reviewed-by: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Jan, 2011
1 commit
-
dcache_lock no longer protects anything. remove it.
Signed-off-by: Nick Piggin
02 Dec, 2010
1 commit
-
NFS needs to be able to release objects that are stored in the page
cache once the page itself is no longer visible from the page cache.This patch adds a callback to the address space operations that allows
filesystems to perform page cleanups once the page has been removed
from the page cache.Original patch by: Linus Torvalds
[trondmy: cover the cases of invalidate_inode_pages2() and
truncate_inode_pages()]
Signed-off-by: Trond Myklebust
12 Nov, 2010
2 commits
-
Salman Qazi describes the following radix-tree bug:
In the following case, we get can get a deadlock:
0. The radix tree contains two items, one has the index 0.
1. The reader (in this case find_get_pages) takes the rcu_read_lock.
2. The reader acquires slot(s) for item(s) including the index 0 item.
3. The non-zero index item is deleted, and as a consequence the other item is
moved to the root of the tree. The place where it used to be is queued for
deletion after the readers finish.
3b. The zero item is deleted, removing it from the direct slot, it remains in
the rcu-delayed indirect node.
4. The reader looks at the index 0 slot, and finds that the page has 0 ref
count
5. The reader looks at it again, hoping that the item will either be freed or
the ref count will increase. This never happens, as the slot it is looking
at will never be updated. Also, this slot can never be reclaimed because
the reader is holding rcu_read_lock and is in an infinite loop.The fix is to re-use the same "indirect" pointer case that requires a slot
lookup retry into a general "retry the lookup" bit.Signed-off-by: Nick Piggin
Reported-by: Salman Qazi
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
70 hours into some stress tests of a 2.6.32-based enterprise kernel, we
ran into a NULL dereference in here:int block_is_partially_uptodate(struct page *page, read_descriptor_t *desc,
unsigned long from)
{
----> struct inode *inode = page->mapping->host;It looks like page->mapping was the culprit. (xmon trace is below).
After closer examination, I realized that do_generic_file_read() does a
find_get_page(), and eventually locks the page before calling
block_is_partially_uptodate(). However, it doesn't revalidate the
page->mapping after the page is locked. So, there's a small window
between the find_get_page() and ->is_partially_uptodate() where the page
could get truncated and page->mapping cleared.We _have_ a reference, so it can't get reclaimed, but it certainly
can be truncated.I think the correct thing is to check page->mapping after the
trylock_page(), and jump out if it got truncated. This patch has been
running in the test environment for a month or so now, and we have not
seen this bug pop up again.xmon info:
1f:mon> e
cpu 0x1f: Vector: 300 (Data Access) at [c0000002ae36f770]
pc: c0000000001e7a6c: .block_is_partially_uptodate+0xc/0x100
lr: c000000000142944: .generic_file_aio_read+0x1e4/0x770
sp: c0000002ae36f9f0
msr: 8000000000009032
dar: 0
dsisr: 40000000
current = 0xc000000378f99e30
paca = 0xc000000000f66300
pid = 21946, comm = bash
1f:mon> r
R00 = 0025c0500000006d R16 = 0000000000000000
R01 = c0000002ae36f9f0 R17 = c000000362cd3af0
R02 = c000000000e8cd80 R18 = ffffffffffffffff
R03 = c0000000031d0f88 R19 = 0000000000000001
R04 = c0000002ae36fa68 R20 = c0000003bb97b8a0
R05 = 0000000000000000 R21 = c0000002ae36fa68
R06 = 0000000000000000 R22 = 0000000000000000
R07 = 0000000000000001 R23 = c0000002ae36fbb0
R08 = 0000000000000002 R24 = 0000000000000000
R09 = 0000000000000000 R25 = c000000362cd3a80
R10 = 0000000000000000 R26 = 0000000000000002
R11 = c0000000001e7b60 R27 = 0000000000000000
R12 = 0000000042000484 R28 = 0000000000000001
R13 = c000000000f66300 R29 = c0000003bb97b9b8
R14 = 0000000000000001 R30 = c000000000e28a08
R15 = 000000000000ffff R31 = c0000000031d0f88
pc = c0000000001e7a6c .block_is_partially_uptodate+0xc/0x100
lr = c000000000142944 .generic_file_aio_read+0x1e4/0x770
msr = 8000000000009032 cr = 22000488
ctr = c0000000001e7a60 xer = 0000000020000000 trap = 300
dar = 0000000000000000 dsisr = 40000000
1f:mon> t
[link register ] c000000000142944 .generic_file_aio_read+0x1e4/0x770
[c0000002ae36f9f0] c000000000142a14 .generic_file_aio_read+0x2b4/0x770 (unreliable)
[c0000002ae36fb40] c0000000001b03e4 .do_sync_read+0xd4/0x160
[c0000002ae36fce0] c0000000001b153c .vfs_read+0xec/0x1f0
[c0000002ae36fd80] c0000000001b1768 .SyS_read+0x58/0xb0
[c0000002ae36fe30] c00000000000852c syscall_exit+0x0/0x40
--- Exception: c00 (System Call) at 00000080a840bc54
SP (fffca15df30) is in userspace
1f:mon> di c0000000001e7a6c
c0000000001e7a6c e9290000 ld r9,0(r9)
c0000000001e7a70 418200c0 beq c0000000001e7b30 # .block_is_partially_uptodate+0xd0/0x100
c0000000001e7a74 e9440008 ld r10,8(r4)
c0000000001e7a78 78a80020 clrldi r8,r5,32
c0000000001e7a7c 3c000001 lis r0,1
c0000000001e7a80 812900a8 lwz r9,168(r9)
c0000000001e7a84 39600001 li r11,1
c0000000001e7a88 7c080050 subf r0,r8,r0
c0000000001e7a8c 7f805040 cmplw cr7,r0,r10
c0000000001e7a90 7d6b4830 slw r11,r11,r9
c0000000001e7a94 796b0020 clrldi r11,r11,32
c0000000001e7a98 419d00a8 bgt cr7,c0000000001e7b40 # .block_is_partially_uptodate+0xe0/0x100
c0000000001e7a9c 7fa55840 cmpld cr7,r5,r11
c0000000001e7aa0 7d004214 add r8,r0,r8
c0000000001e7aa4 79080020 clrldi r8,r8,32
c0000000001e7aa8 419c0078 blt cr7,c0000000001e7b20 # .block_is_partially_uptodate+0xc0/0x100Signed-off-by: Dave Hansen
Reviewed-by: Minchan Kim
Reviewed-by: Johannes Weiner
Acked-by: Rik van Riel
Cc:
Cc:
Cc: Christoph Hellwig
Cc: Al Viro
Cc: Minchan Kim
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 Nov, 2010
1 commit
-
This slipped by when unifying the filemap and swap versions of
lock_page_or_retry()...Signed-off-by: Michel Lespinasse
Acked-by: Rik van Riel
Signed-off-by: Linus Torvalds
27 Oct, 2010
3 commits
-
'end' shadows earlier one and is not necessary at all. Remove it and use
'pos' instead. This removes following sparse warnings:mm/filemap.c:2180:24: warning: symbol 'end' shadows an earlier one
mm/filemap.c:2132:25: originally declared hereSigned-off-by: Namhyung Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This change reduces mmap_sem hold times that are caused by waiting for
disk transfers when accessing file mapped VMAs.It introduces the VM_FAULT_ALLOW_RETRY flag, which indicates that the call
site wants mmap_sem to be released if blocking on a pending disk transfer.
In that case, filemap_fault() returns the VM_FAULT_RETRY status bit and
do_page_fault() will then re-acquire mmap_sem and retry the page fault.It is expected that the retry will hit the same page which will now be
cached, and thus it will complete with a low mmap_sem hold time.Tests:
- microbenchmark: thread A mmaps a large file and does random read accesses
to the mmaped area - achieves about 55 iterations/s. Thread B does
mmap/munmap in a loop at a separate location - achieves 55 iterations/s
before, 15000 iterations/s after.- We are seeing related effects in some applications in house, which show
significant performance regressions when running without this change.[akpm@linux-foundation.org: fix warning & crash]
Signed-off-by: Michel Lespinasse
Acked-by: Rik van Riel
Acked-by: Linus Torvalds
Cc: Nick Piggin
Reviewed-by: Wu Fengguang
Cc: Ying Han
Cc: Peter Zijlstra
Cc: Ingo Molnar
Cc: Thomas Gleixner
Acked-by: "H. Peter Anvin"
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Introduce a single location where filemap_fault() locks the desired page.
There used to be two such places, depending if the initial find_get_page()
was successful or not.Signed-off-by: Michel Lespinasse
Acked-by: Rik van Riel
Acked-by: Linus Torvalds
Cc: Nick Piggin
Reviewed-by: Wu Fengguang
Cc: Ying Han
Cc: Peter Zijlstra
Cc: Ingo Molnar
Cc: Thomas Gleixner
Cc: "H. Peter Anvin"
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
10 Aug, 2010
1 commit
-
No real bugs, just some dead code and some fixups.
Signed-off-by: Andi Kleen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
31 May, 2010
1 commit
-
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
mm: export generic_pipe_buf_*() to modules
fuse: support splice() reading from fuse device
fuse: allow splice to move pages
mm: export remove_from_page_cache() to modules
mm: export lru_cache_add_*() to modules
fuse: support splice() writing to fuse device
fuse: get page reference for readpages
fuse: use get_user_pages_fast()
fuse: remove unneeded variable
28 May, 2010
1 commit
-
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (27 commits)
Btrfs: add more error checking to btrfs_dirty_inode
Btrfs: allow unaligned DIO
Btrfs: drop verbose enospc printk
Btrfs: Fix block generation verification race
Btrfs: fix preallocation and nodatacow checks in O_DIRECT
Btrfs: avoid ENOSPC errors in btrfs_dirty_inode
Btrfs: move O_DIRECT space reservation to btrfs_direct_IO
Btrfs: rework O_DIRECT enospc handling
Btrfs: use async helpers for DIO write checksumming
Btrfs: don't walk around with task->state != TASK_RUNNING
Btrfs: do aio_write instead of write
Btrfs: add basic DIO read/write support
direct-io: do not merge logically non-contiguous requests
direct-io: add a hook for the fs to provide its own submit_bio function
fs: allow short direct-io reads to be completed via buffered IO
Btrfs: Metadata ENOSPC handling for balance
Btrfs: Pre-allocate space for data relocation
Btrfs: Metadata ENOSPC handling for tree log
Btrfs: Metadata reservation for orphan inodes
Btrfs: Introduce global metadata reservation
...
27 May, 2010
1 commit
-
I/O errors can happen due to temporary failures, like multipath
errors or losing network contact with the iSCSI server. Because
of that, the VM will retry readpage on the page.However, do_generic_file_read does not clear PG_error. This
causes the system to be unable to actually use the data in the
page cache page, even if the subsequent readpage completes
successfully!The function filemap_fault has had a ClearPageError before
readpage forever. This patch simply adds the same to
do_generic_file_read.Signed-off-by: Jeff Moyer
Signed-off-by: Rik van Riel
Acked-by: Larry Woodman
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds
25 May, 2010
4 commits
-
Before applying this patch, cpuset updates task->mems_allowed and
mempolicy by setting all new bits in the nodemask first, and clearing all
old unallowed bits later. But in the way, the allocator may find that
there is no node to alloc memory.The reason is that cpuset rebinds the task's mempolicy, it cleans the
nodes which the allocater can alloc pages on, for example:(mpol: mempolicy)
task1 task1's mpol task2
alloc page 1
alloc on node0? NO 1
1 change mems from 1 to 0
1 rebind task1's mpol
0-1 set new bits
0 clear disallowed bits
alloc on node1? NO 0
...
can't alloc page
goto oomThis patch fixes this problem by expanding the nodes range first(set newly
allowed bits) and shrink it lazily(clear newly disallowed bits). So we
use a variable to tell the write-side task that read-side task is reading
nodemask, and the write-side task clears newly disallowed nodes after
read-side task ends the current memory allocation.[akpm@linux-foundation.org: fix spello]
Signed-off-by: Miao Xie
Cc: David Rientjes
Cc: Nick Piggin
Cc: Paul Menage
Cc: Lee Schermerhorn
Cc: Hugh Dickins
Cc: Ravikiran Thirumalai
Cc: KOSAKI Motohiro
Cc: Christoph Lameter
Cc: Andi Kleen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Shaohua Li reported parallel file copy on tmpfs can lead to OOM killer.
This is regression of caused by commit 9ff473b9a7 ("vmscan: evict
streaming IO first"). Wow, It is 2 years old patch!Currently, tmpfs file cache is inserted active list at first. This means
that the insertion doesn't only increase numbers of pages in anon LRU, but
it also reduces anon scanning ratio. Therefore, vmscan will get totally
confused. It scans almost only file LRU even though the system has plenty
unused tmpfs pages.Historically, lru_cache_add_active_anon() was used for two reasons.
1) Intend to priotize shmem page rather than regular file cache.
2) Intend to avoid reclaim priority inversion of used once pages.But we've lost both motivation because (1) Now we have separate anon and
file LRU list. then, to insert active list doesn't help such priotize.
(2) In past, one pte access bit will cause page activation. then to
insert inactive list with pte access bit mean higher priority than to
insert active list. Its priority inversion may lead to uninteded lru
chun. but it was already solved by commit 645747462 (vmscan: detect
mapped file pages used only once). (Thanks Hannes, you are great!)Thus, now we can use lru_cache_add_anon() instead.
Signed-off-by: KOSAKI Motohiro
Reported-by: Shaohua Li
Reviewed-by: Wu Fengguang
Reviewed-by: Johannes Weiner
Reviewed-by: Rik van Riel
Reviewed-by: Minchan Kim
Acked-by: Hugh Dickins
Cc: Henrique de Moraes Holschuh
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This is similar to what already happens in the write case. If we have a short
read while doing O_DIRECT, instead of just returning, fallthrough and try to
read the rest via buffered IO. BTRFS needs this because if we encounter a
compressed or inline extent during DIO, we need to fallback on buffered. If the
extent is compressed we need to read the entire thing into memory and
de-compress it into the users pages. I have tested this with fsx and everything
works great. Thanks,Signed-off-by: Josef Bacik
Signed-off-by: Chris Mason -
This is needed to enable moving pages into the page cache in fuse with
splice(..., SPLICE_F_MOVE).Signed-off-by: Miklos Szeredi
30 Mar, 2010
1 commit
-
…it slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
07 Mar, 2010
1 commit
-
Make sure compiler won't do weird things with limits. E.g. fetching them
twice may return 2 different values after writable limits are implemented.I.e. either use rlimit helpers added in
3e10e716abf3c71bdb5d86b8f507f9e72236c9cd ("resource: add helpers for
fetching rlimits") or ACCESS_ONCE if not applicable.Signed-off-by: Jiri Slaby
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Mar, 2010
1 commit
-
No one is calling this anymore as everyone has switched to
invalidate_mapping_pages long time ago. Also update a few
references to it in comments. nfs has two more, but I can't
easily figure what they are actually referring to, so I left
them as-is.Signed-off-by: Christoph Hellwig
Signed-off-by: Al Viro
03 Feb, 2010
1 commit
-
The cache alias problem will happen if the changes of user shared mapping
is not flushed before copying, then user and kernel mapping may be mapped
into two different cache line, it is impossible to guarantee the coherence
after iov_iter_copy_from_user_atomic. So the right steps should be:flush_dcache_page(page);
kmap_atomic(page);
write to page;
kunmap_atomic(page);
flush_dcache_page(page);More precisely, we might create two new APIs flush_dcache_user_page and
flush_dcache_kern_page to replace the two flush_dcache_page accordingly.Here is a snippet tested on omap2430 with VIPT cache, and I think it is
not ARM-specific:int val = 0x11111111;
fd = open("abc", O_RDWR);
addr = mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
*(addr+0) = 0x44444444;
tmp = *(addr+0);
*(addr+1) = 0x77777777;
write(fd, &val, sizeof(int));
close(fd);The results are not always 0x11111111 0x77777777 at the beginning as expected. Sometimes we see 0x44444444 0x77777777.
Signed-off-by: Anfei
Cc: Russell King
Cc: Miklos Szeredi
Cc: Nick Piggin
Cc:
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
28 Jan, 2010
1 commit
-
It's a simplified 'read_cache_page()' which takes a page allocation
flag, so that different paths can control how aggressive the memory
allocations are that populate a address space.In particular, the intel GPU object mapping code wants to be able to do
a certain amount of own internal memory management by automatically
shrinking the address space when memory starts getting tight. This
allows it to dynamically use different memory allocation policies on a
per-allocation basis, rather than depend on the (static) address space
gfp policy.The actual new function is a one-liner, but re-organizing the helper
functions to the point where you can do this with a single line of code
is what most of the patch is all about.Tested-by: Chris Wilson
Signed-off-by: Linus Torvalds
17 Dec, 2009
1 commit
-
In the case of direct I/O falling back to buffered I/O we sync data
twice currently: once at the end of generic_file_buffered_write using
filemap_write_and_wait_range and once a little later in
__generic_file_aio_write using do_sync_mapping_range with all flags set.The wait before write of the do_sync_mapping_range call does not make
any sense, so just keep the filemap_write_and_wait_range call and move
it to the right spot.Signed-off-by: Christoph Hellwig
Signed-off-by: Al Viro
10 Dec, 2009
1 commit
-
All callers really want the more logical filemap_fdatawait_range interface,
so convert them to use it and merge wait_on_page_writeback_range into
filemap_fdatawait_range.Signed-off-by: Christoph Hellwig
Signed-off-by: Jan Kara
04 Dec, 2009
1 commit
-
That is "success", "unknown", "through", "performance", "[re|un]mapping"
, "access", "default", "reasonable", "[con]currently", "temperature"
, "channel", "[un]used", "application", "example","hierarchy", "therefore"
, "[over|under]flow", "contiguous", "threshold", "enough" and others.Signed-off-by: André Goddard Rosa
Signed-off-by: Jiri Kosina
