01 Apr, 2009
2 commits
-
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=9838
On i386, HZ=1000, jiffies_to_clock_t() converts time in a somewhat strange
way from the user's point of view:# echo 500 >/proc/sys/vm/dirty_writeback_centisecs
# cat /proc/sys/vm/dirty_writeback_centisecs
499So, we have 5000 jiffies converted to only 499 clock ticks and reported
back.TICK_NSEC = 999848
ACTHZ = 256039Keeping in-kernel variable in units passed from userspace will fix issue
of course, but this probably won't be right for every sysctl.[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alexey Dobriyan
Cc: Peter Zijlstra
Cc: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add a helper function account_page_dirtied(). Use that from two
callsites. reiser4 adds a function which adds a third callsite.Signed-off-by: Edward Shishkin
Cc: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Mar, 2009
1 commit
-
Enlarge default dirty ratios from 5/10 to 10/20. This fixes [Bug
#12809] iozone regression with 2.6.29-rc6.The iozone benchmarks are performed on a 1200M file, with 8GB ram.
iozone -i 0 -i 1 -i 2 -i 3 -i 4 -r 4k -s 64k -s 512m -s 1200m -b tmp.xls
iozone -B -r 4k -s 64k -s 512m -s 1200m -b tmp.xlsThe performance regression is triggered by commit 1cf6e7d83bf3(mm: task
dirty accounting fix), which makes more correct/thorough dirty
accounting.The default 5/10 dirty ratios were picked (a) with the old dirty logic
and (b) largely at random and (c) designed to be aggressive. In
particular, that (a) means that having fixed some of the dirty
accounting, maybe the real bug is now that it was always too aggressive,
just hidden by an accounting issue.The enlarged 10/20 dirty ratios are just about enough to fix the regression.
[ We will have to look at how this affects the old fsync() latency issue,
but that probably will need independent work. - Linus ]Cc: Nick Piggin
Cc: Peter Zijlstra
Reported-by: "Lin, Ming M"
Tested-by: "Lin, Ming M"
Signed-off-by: Wu Fengguang
Signed-off-by: Linus Torvalds
19 Feb, 2009
1 commit
-
YAMAMOTO-san noticed that task_dirty_inc doesn't seem to be called properly for
cases where set_page_dirty is not used to dirty a page (eg. mark_buffer_dirty).Additionally, there is some inconsistency about when task_dirty_inc is
called. It is used for dirty balancing, however it even gets called for
__set_page_dirty_no_writeback.So rather than increment it in a set_page_dirty wrapper, move it down to
exactly where the dirty page accounting stats are incremented.Cc: YAMAMOTO Takashi
Signed-off-by: Nick Piggin
Acked-by: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Feb, 2009
1 commit
-
A bug was introduced into write_cache_pages cyclic writeout by commit
31a12666d8f0c22235297e1c1575f82061480029 ("mm: write_cache_pages cyclic
fix"). The intention (and comments) is that we should cycle back and
look for more dirty pages at the beginning of the file if there is no
more work to be done.But the !done condition was dropped from the test. This means that any
time the page writeout loop breaks (eg. due to nr_to_write == 0), we
will set index to 0, then goto again. This will set done_index to
index, then find done is set, so will proceed to the end of the
function. When updating mapping->writeback_index for cyclic writeout,
we now use done_index == 0, so we're always cycling back to 0.This seemed to be causing random mmap writes (slapadd and iozone) to
start writing more pages from the LRU and writeout would slowdown, and
caused bugzilla entryhttp://bugzilla.kernel.org/show_bug.cgi?id=12604
about Berkeley DB slowing down dramatically.
With this patch, iozone random write performance is increased nearly
5x on my system (iozone -B -r 4k -s 64k -s 512m -s 1200m on ext2).Signed-off-by: Nick Piggin
Reported-and-tested-by: Jan Kara
Signed-off-by: Linus Torvalds
12 Feb, 2009
2 commits
-
Commit dcf6a79dda5cc2a2bec183e50d829030c0972aaa ("write-back: fix
nr_to_write counter") fixed nr_to_write counter, but didn't set the break
condition properly.If nr_to_write == 0 after being decremented it will loop one more time
before setting done = 1 and breaking the loop.[akpm@linux-foundation.org: coding-style fixes]
Cc: Artem Bityutskiy
Acked-by: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
We need to pass an unsigned long as the minimum, because it gets casted
to an unsigned long in the sysctl handler. If we pass an int, we'll
access four more bytes on 64bit arches, resulting in a random minimum
value.[rientjes@google.com: fix type of `old_bytes']
Signed-off-by: Sven Wegener
Cc: Peter Zijlstra
Cc: Dave Chinner
Cc: Christoph Lameter
Cc: David Rientjes
Signed-off-by: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Feb, 2009
1 commit
-
Commit 05fe478dd04e02fa230c305ab9b5616669821dd3 introduced some
@wbc->nr_to_write breakage.It made the following changes:
1. Decrement wbc->nr_to_write instead of nr_to_write
2. Decrement wbc->nr_to_write _only_ if wbc->sync_mode == WB_SYNC_NONE
3. If synced nr_to_write pages, stop only if if wbc->sync_mode ==
WB_SYNC_NONE, otherwise keep going.However, according to the commit message, the intention was to only make
change 3. Change 1 is a bug. Change 2 does not seem to be necessary,
and it breaks UBIFS expectations, so if needed, it should be done
separately later. And change 2 does not seem to be documented in the
commit message.This patch does the following:
1. Undo changes 1 and 2
2. Add a comment explaining change 3 (it very useful to have comments
in _code_, not only in the commit).Signed-off-by: Artem Bityutskiy
Acked-by: Nick Piggin
Cc: Andrew Morton
Signed-off-by: Linus Torvalds
07 Jan, 2009
10 commits
-
This change introduces two new sysctls to /proc/sys/vm:
dirty_background_bytes and dirty_bytes.dirty_background_bytes is the counterpart to dirty_background_ratio and
dirty_bytes is the counterpart to dirty_ratio.With growing memory capacities of individual machines, it's no longer
sufficient to specify dirty thresholds as a percentage of the amount of
dirtyable memory over the entire system.dirty_background_bytes and dirty_bytes specify quantities of memory, in
bytes, that represent the dirty limits for the entire system. If either
of these values is set, its value represents the amount of dirty memory
that is needed to commence either background or direct writeback.When a `bytes' or `ratio' file is written, its counterpart becomes a
function of the written value. For example, if dirty_bytes is written to
be 8096, 8K of memory is required to commence direct writeback.
dirty_ratio is then functionally equivalent to 8K / the amount of
dirtyable memory:dirtyable_memory = free pages + mapped pages + file cache
dirty_background_bytes = dirty_background_ratio * dirtyable_memory
-or-
dirty_background_ratio = dirty_background_bytes / dirtyable_memoryAND
dirty_bytes = dirty_ratio * dirtyable_memory
-or-
dirty_ratio = dirty_bytes / dirtyable_memoryOnly one of dirty_background_bytes and dirty_background_ratio may be
specified at a time, and only one of dirty_bytes and dirty_ratio may be
specified. When one sysctl is written, the other appears as 0 when read.The `bytes' files operate on a page size granularity since dirty limits
are compared with ZVC values, which are in page units.Prior to this change, the minimum dirty_ratio was 5 as implemented by
get_dirty_limits() although /proc/sys/vm/dirty_ratio would show any user
written value between 0 and 100. This restriction is maintained, but
dirty_bytes has a lower limit of only one page.Also prior to this change, the dirty_background_ratio could not equal or
exceed dirty_ratio. This restriction is maintained in addition to
restricting dirty_background_bytes. If either background threshold equals
or exceeds that of the dirty threshold, it is implicitly set to half the
dirty threshold.Acked-by: Peter Zijlstra
Cc: Dave Chinner
Cc: Christoph Lameter
Signed-off-by: David Rientjes
Cc: Andrea Righi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The background dirty and dirty limits are better defined with type
specifiers of unsigned long since negative writeback thresholds are not
possible.These values, as returned by get_dirty_limits(), are normally compared
with ZVC values to determine whether writeback shall commence or be
throttled. Such page counts cannot be negative, so declaring the page
limits as signed is unnecessary.Acked-by: Peter Zijlstra
Cc: Dave Chinner
Cc: Christoph Lameter
Signed-off-by: David Rientjes
Cc: Andrea Righi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Now that we have the early-termination logic in place, it makes sense to
bail out early in all other cases where done is set to 1.Signed-off-by: Nick Piggin
Cc: Chris Mason
Cc: Dave Chinner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Terminate the write_cache_pages loop upon encountering the first page past
end, without locking the page. Pages cannot have their index change when
we have a reference on them (truncate, eg truncate_inode_pages_range
performs the same check without the page lock).Signed-off-by: Nick Piggin
Cc: Chris Mason
Cc: Dave Chinner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In write_cache_pages, if we get stuck behind another process that is
cleaning pages, we will be forced to wait for them to finish, then perform
our own writeout (if it was redirtied during the long wait), then wait for
that.If a page under writeout is still clean, we can skip waiting for it (if
we're part of a data integrity sync, we'll be waiting for all writeout
pages afterwards, so we'll still be waiting for the other guy's write
that's cleaned the page).Signed-off-by: Nick Piggin
Cc: Chris Mason
Cc: Dave Chinner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Get rid of some complex expressions from flow control statements, add a
comment, remove some duplicate code.Signed-off-by: Nick Piggin
Cc: Chris Mason
Cc: Dave Chinner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In write_cache_pages, nr_to_write is heeded even for data-integrity syncs,
so the function will return success after writing out nr_to_write pages,
even if that was not sufficient to guarantee data integrity.The callers tend to set it to values that could break data interity
semantics easily in practice. For example, nr_to_write can be set to
mapping->nr_pages * 2, however if a file has a single, dirty page, then
fsync is called, subsequent pages might be concurrently added and dirtied,
then write_cache_pages might writeout two of these newly dirty pages,
while not writing out the old page that should have been written out.Fix this by ignoring nr_to_write if it is a data integrity sync.
This is a data integrity bug.
The reason this has been done in the past is to avoid stalling sync
operations behind page dirtiers."If a file has one dirty page at offset 1000000000000000 then someone
does an fsync() and someone else gets in first and starts madly writing
pages at offset 0, we want to write that page at 1000000000000000.
Somehow."What we do today is return success after an arbitrary amount of pages are
written, whether or not we have provided the data-integrity semantics that
the caller has asked for. Even this doesn't actually fix all stall cases
completely: in the above situation, if the file has a huge number of pages
in pagecache (but not dirty), then mapping->nrpages is going to be huge,
even if pages are being dirtied.This change does indeed make the possibility of long stalls lager, and
that's not a good thing, but lying about data integrity is even worse. We
have to either perform the sync, or return -ELINUXISLAME so at least the
caller knows what has happened.There are subsequent competing approaches in the works to solve the stall
problems properly, without compromising data integrity.Signed-off-by: Nick Piggin
Cc: Chris Mason
Cc: Dave Chinner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In write_cache_pages, if ret signals a real error, but we still have some
pages left in the pagevec, done would be set to 1, but the remaining pages
would continue to be processed and ret will be overwritten in the process.It could easily be overwritten with success, and thus success will be
returned even if there is an error. Thus the caller is told all writes
succeeded, wheras in reality some did not.Fix this by bailing immediately if there is an error, and retaining the
first error code.This is a data integrity bug.
Signed-off-by: Nick Piggin
Cc: Chris Mason
Cc: Dave Chinner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
We'd like to break out of the loop early in many situations, however the
existing code has been setting mapping->writeback_index past the final
page in the pagevec lookup for cyclic writeback. This is a problem if we
don't process all pages up to the final page.Currently the code mostly keeps writeback_index reasonable and hacked
around this by not breaking out of the loop or writing pages outside the
range in these cases. Keep track of a real "done index" that enables us
to terminate the loop in a much more flexible manner.Needed by the subsequent patch to preserve writepage errors, and then
further patches to break out of the loop early for other reasons. However
there are no functional changes with this patch alone.Signed-off-by: Nick Piggin
Cc: Chris Mason
Cc: Dave Chinner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In write_cache_pages, scanned == 1 is supposed to mean that cyclic
writeback has circled through zero, thus we should not circle again.
However it gets set to 1 after the first successful pagevec lookup. This
leads to cases where not enough data gets written.Counterexample: file with first 10 pages dirty, writeback_index == 5,
nr_to_write == 10. Then the 5 last pages will be found, and scanned will
be set to 1, after writing those out, we will not cycle back to get the
first 5.Rework this logic, now we'll always cycle unless we started off from index
0. When cycling, only write out as far as 1 page before the start page
from the first cycle (so we don't write parts of the file twice).Signed-off-by: Nick Piggin
Cc: Chris Mason
Cc: Dave Chinner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
20 Oct, 2008
1 commit
-
Split the LRU lists in two, one set for pages that are backed by real file
systems ("file") and one for pages that are backed by memory and swap
("anon"). The latter includes tmpfs.The advantage of doing this is that the VM will not have to scan over lots
of anonymous pages (which we generally do not want to swap out), just to
find the page cache pages that it should evict.This patch has the infrastructure and a basic policy to balance how much
we scan the anon lists and how much we scan the file lists. The big
policy changes are in separate patches.[lee.schermerhorn@hp.com: collect lru meminfo statistics from correct offset]
[kosaki.motohiro@jp.fujitsu.com: prevent incorrect oom under split_lru]
[kosaki.motohiro@jp.fujitsu.com: fix pagevec_move_tail() doesn't treat unevictable page]
[hugh@veritas.com: memcg swapbacked pages active]
[hugh@veritas.com: splitlru: BDI_CAP_SWAP_BACKED]
[akpm@linux-foundation.org: fix /proc/vmstat units]
[nishimura@mxp.nes.nec.co.jp: memcg: fix handling of shmem migration]
[kosaki.motohiro@jp.fujitsu.com: adjust Quicklists field of /proc/meminfo]
[kosaki.motohiro@jp.fujitsu.com: fix style issue of get_scan_ratio()]
Signed-off-by: Rik van Riel
Signed-off-by: Lee Schermerhorn
Signed-off-by: KOSAKI Motohiro
Signed-off-by: Hugh Dickins
Signed-off-by: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Oct, 2008
1 commit
-
People can use the real name an an index into MAINTAINERS to find the
current email address.Signed-off-by: Francois Cami
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
16 Oct, 2008
1 commit
-
If no_nrwrite_index_update is set we don't update nr_to_write and
address space writeback_index in write_cache_pages. This change
enables a file system to skip these updates in write_cache_pages and do
them in the writepages() callback. This patch will be followed by an
ext4 patch that make use of these new flags.Signed-off-by: Aneesh Kumar K.V
Signed-off-by: "Theodore Ts'o"
CC: linux-fsdevel@vger.kernel.org
14 Oct, 2008
1 commit
-
Ext4 was the only user of range_cont writeback mode and ext4 switched
to a different method. So remove the range_cont mode which is not used
in the kernel.Signed-off-by: Aneesh Kumar K.V
Signed-off-by: "Theodore Ts'o"
CC: linux-fsdevel@vger.kernel.org
27 Jul, 2008
1 commit
-
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
15 Jul, 2008
1 commit
-
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (61 commits)
ext4: Documention update for new ordered mode and delayed allocation
ext4: do not set extents feature from the kernel
ext4: Don't allow nonextenst mount option for large filesystem
ext4: Enable delalloc by default.
ext4: delayed allocation i_blocks fix for stat
ext4: fix delalloc i_disksize early update issue
ext4: Handle page without buffers in ext4_*_writepage()
ext4: Add ordered mode support for delalloc
ext4: Invert lock ordering of page_lock and transaction start in delalloc
mm: Add range_cont mode for writeback
ext4: delayed allocation ENOSPC handling
percpu_counter: new function percpu_counter_sum_and_set
ext4: Add delayed allocation support in data=writeback mode
vfs: add hooks for ext4's delayed allocation support
jbd2: Remove data=ordered mode support using jbd buffer heads
ext4: Use new framework for data=ordered mode in JBD2
jbd2: Implement data=ordered mode handling via inodes
vfs: export filemap_fdatawrite_range()
ext4: Fix lock inversion in ext4_ext_truncate()
ext4: Invert the locking order of page_lock and transaction start
...
12 Jul, 2008
1 commit
-
Filesystems like ext4 needs to start a new transaction in
the writepages for block allocation. This happens with delayed
allocation and there is limit to how many credits we can request
from the journal layer. So we call write_cache_pages multiple
times with wbc->nr_to_write set to the maximum possible value
limitted by the max journal credits available.Add a new mode to writeback that enables us to handle this
behaviour. In the new mode we update the wbc->range_start
to point to the new offset to be written. Next call to
call to write_cache_pages will start writeout from specified
range_start offset. In the new mode we also limit writing
to the specified wbc->range_end.Signed-off-by: Aneesh Kumar K.V
Signed-off-by: Mingming Cao
Acked-by: Jan Kara
Signed-off-by: "Theodore Ts'o"
24 May, 2008
1 commit
-
Currently there is no protection from the root user to use up all of
memory for trace buffers. If the root user allocates too many entries,
the OOM killer might start kill off all tasks.This patch adds an algorith to check the following condition:
pages_requested > (freeable_memory + current_trace_buffer_pages) / 4
If the above is met then the allocation fails. The above prevents more
than 1/4th of freeable memory from being used by trace buffers.To determine the freeable_memory, I made determine_dirtyable_memory in
mm/page-writeback.c global.Special thanks goes to Peter Zijlstra for suggesting the above calculation.
Signed-off-by: Steven Rostedt
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner
30 Apr, 2008
6 commits
-
Fuse will use temporary buffers to write back dirty data from memory mappings
(normal writes are done synchronously). This is needed, because there cannot
be any guarantee about the time in which a write will complete.By using temporary buffers, from the MM's point if view the page is written
back immediately. If the writeout was due to memory pressure, this
effectively migrates data from a full zone to a less full zone.This patch adds a new counter (NR_WRITEBACK_TEMP) for the number of pages used
as temporary buffers.[Lee.Schermerhorn@hp.com: add vmstat_text for NR_WRITEBACK_TEMP]
Signed-off-by: Miklos Szeredi
Cc: Christoph Lameter
Signed-off-by: Lee Schermerhorn
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fuse needs this for writable mmap support.
Signed-off-by: Miklos Szeredi
Cc: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add a new BDI capability flag: BDI_CAP_NO_ACCT_WB. If this flag is
set, then don't update the per-bdi writeback stats from
test_set_page_writeback() and test_clear_page_writeback().Misc cleanups:
- convert bdi_cap_writeback_dirty() and friends to static inline functions
- create a flag that includes all three dirty/writeback related flags,
since almst all users will want to have them toghetherSigned-off-by: Miklos Szeredi
Cc: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add "max_ratio" to /sys/class/bdi. This indicates the maximum percentage of
the global dirty threshold allocated to this bdi.[mszeredi@suse.cz]
- fix parsing in max_ratio_store().
- export bdi_set_max_ratio() to modules
- limit bdi_dirty with bdi->max_ratio
- document new sysfs attributeSigned-off-by: Peter Zijlstra
Signed-off-by: Miklos Szeredi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Under normal circumstances each device is given a part of the total write-back
cache that relates to its current avg writeout speed in relation to the other
devices.min_ratio - allows one to assign a minimum portion of the write-back cache to
a particular device. This is useful in situations where you might want to
provide a minimum QoS. (One request for this feature came from flash based
storage people who wanted to avoid writing out at all costs - they of course
needed some pdflush hacks as well)max_ratio - allows one to assign a maximum portion of the dirty limit to a
particular device. This is useful in situations where you want to avoid one
device taking all or most of the write-back cache. Eg. an NFS mount that is
prone to get stuck, or a FUSE mount which you don't trust to play fair.Add "min_ratio" to /sys/class/bdi. This indicates the minimum percentage of
the global dirty threshold allocated to this bdi.[mszeredi@suse.cz]
- fix parsing in min_ratio_store()
- document new sysfs attributeSigned-off-by: Peter Zijlstra
Signed-off-by: Miklos Szeredi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Provide a place in sysfs (/sys/class/bdi) for the backing_dev_info object.
This allows us to see and set the various BDI specific variables.In particular this properly exposes the read-ahead window for all relevant
users and /sys/block//queue/read_ahead_kb should be deprecated.With patient help from Kay Sievers and Greg KH
[mszeredi@suse.cz]
- split off NFS and FUSE changes into separate patches
- document new sysfs attributes under Documentation/ABI
- do bdi_class_init as a core_initcall, otherwise the "default" BDI
won't be initialized
- remove bdi_init_fmt macro, it's not used very much[akpm@linux-foundation.org: fix ia64 warning]
Signed-off-by: Peter Zijlstra
Cc: Kay Sievers
Acked-by: Greg KH
Cc: Trond Myklebust
Signed-off-by: Miklos Szeredi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Feb, 2008
4 commits
-
After making dirty a 100M file, the normal behavior is to start the
writeback for all data after 30s delays. But sometimes the following
happens instead:- after 30s: ~4M
- after 5s: ~4M
- after 5s: all remaining 92MSome analyze shows that the internal io dispatch queues goes like this:
s_io s_more_io
-------------------------
1) 100M,1K 0
2) 1K 96M
3) 0 96M
1) initial state with a 100M file and a 1K file2) 4M written, nr_to_write 0, no more writes(BUG)
nr_to_write > 0 in (3) fools the upper layer to think that data have all
been written out. The big dirty file is actually still sitting in
s_more_io. We cannot simply splice s_more_io back to s_io as soon as s_io
becomes empty, and let the loop in generic_sync_sb_inodes() continue: this
may starve newly expired inodes in s_dirty. It is also not an option to
draw inodes from both s_more_io and s_dirty, an let the loop go on: this
might lead to live locks, and might also starve other superblocks in sync
time(well kupdate may still starve some superblocks, that's another bug).We have to return when a full scan of s_io completes. So nr_to_write > 0
does not necessarily mean that "all data are written". This patch
introduces a flag writeback_control.more_io to indicate that more io should
be done. With it the big dirty file no longer has to wait for the next
kupdate invokation 5s later.In sync_sb_inodes() we only set more_io on super_blocks we actually
visited. This avoids the interaction between two pdflush deamons.Also in __sync_single_inode() we don't blindly keep requeuing the io if the
filesystem cannot progress. Failing to do so may lead to 100% iowait.Tested-by: Mike Snitzer
Signed-off-by: Fengguang Wu
Cc: Michael Rubin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
fastcall is always defined to be empty, remove it
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Harvey Harrison
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add vm.highmem_is_dirtyable toggle
A 32 bit machine with HIGHMEM64 enabled running DCC has an MMAPed file of
approximately 2Gb size which contains a hash format that is written
randomly by the dbclean process. On 2.6.16 this process took a few
minutes. With lowmem only accounting of dirty ratios, this takes about 12
hours of 100% disk IO, all random writes.Include a toggle in /proc/sys/vm/highmem_is_dirtyable which can be set to 1 to
add the highmem back to the total available memory count.[akpm@linux-foundation.org: Fix the CONFIG_DETECT_SOFTLOCKUP=y build]
Signed-off-by: Bron Gondwana
Cc: Ethan Solomita
Cc: Peter Zijlstra
Cc: WU Fengguang
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
task_dirty_limit() can become static.
Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
15 Jan, 2008
1 commit
-
This reverts commit 2e6883bdf49abd0e7f0d9b6297fc3be7ebb2250b, as
requested by Fengguang Wu. It's not quite fully baked yet, and while
there are patches around to fix the problems it caused, they should get
more testing. Says Fengguang: "I'll resend them both for -mm later on,
in a more complete patchset".See
http://bugzilla.kernel.org/show_bug.cgi?id=9738
for some of this discussion.
Requested-by: Fengguang Wu
Cc: Andrew Morton
Cc: Peter Zijlstra
Signed-off-by: Linus Torvalds
16 Nov, 2007
1 commit
-
This code harks back to the days when we didn't count dirty mapped
pages, which led us to try to balance the number of dirty unmapped pages
by how much unmapped memory there was in the system.That makes no sense any more, since now the dirty counts include the
mapped pages. Not to mention that the math doesn't work with HIGHMEM
machines anyway, and causes the unmapped_ratio to potentially turn
negative (which we do catch thanks to clamping it at a minimum value,
but I mention that as an indication of how broken the code is).The code also was written at a time when the default dirty ratio was
much larger, and the unmapped_ratio logic effectively capped that large
dirty ratio a bit. Again, we've since lowered the dirty ratio rather
aggressively, further lessening the point of that code.Acked-by: Peter Zijlstra
Signed-off-by: Linus Torvalds
15 Nov, 2007
1 commit
-
We allow violation of bdi limits if there is a lot of room on the system.
Once we hit half the total limit we start enforcing bdi limits and bdi
ramp-up should happen. Doing it this way avoids many small writeouts on an
otherwise idle system and should also speed up the ramp-up.Signed-off-by: Peter Zijlstra
Reviewed-by: Fengguang Wu
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
20 Oct, 2007
1 commit
-
Spelling fixes in mm/.
Signed-off-by: Simon Arlott
Signed-off-by: Adrian Bunk
