1. 07 1月, 2009 1 次提交
    • N
      mm: write_cache_pages cyclic fix · 31a12666
      Nick Piggin 提交于
      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: NNick Piggin <npiggin@suse.de>
      Cc: Chris Mason <chris.mason@oracle.com>
      Cc: Dave Chinner <david@fromorbit.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      31a12666
  2. 20 10月, 2008 1 次提交
    • R
      vmscan: split LRU lists into anon & file sets · 4f98a2fe
      Rik van Riel 提交于
      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: NRik van Riel <riel@redhat.com>
      Signed-off-by: NLee Schermerhorn <Lee.Schermerhorn@hp.com>
      Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Signed-off-by: NHugh Dickins <hugh@veritas.com>
      Signed-off-by: NDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      4f98a2fe
  3. 17 10月, 2008 1 次提交
  4. 16 10月, 2008 1 次提交
  5. 14 10月, 2008 1 次提交
  6. 27 7月, 2008 1 次提交
  7. 12 7月, 2008 1 次提交
    • A
      mm: Add range_cont mode for writeback · 06d6cf69
      Aneesh Kumar K.V 提交于
      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: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: NMingming Cao <cmm@us.ibm.com>
      Acked-by: NJan Kara <jack@suse.cz>
      Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
      06d6cf69
  8. 24 5月, 2008 1 次提交
    • S
      ftrace: limit trace entries · 3eefae99
      Steven Rostedt 提交于
      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: NSteven Rostedt <srostedt@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      3eefae99
  9. 30 4月, 2008 6 次提交
  10. 06 2月, 2008 4 次提交
    • F
      writeback: speed up writeback of big dirty files · 8bc3be27
      Fengguang Wu 提交于
      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 92M
      
      Some 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 file
      
      2) 4M written, nr_to_write <= 0, so write more
      
      3) 1K 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: NMike Snitzer <snitzer@gmail.com>
      Signed-off-by: NFengguang Wu <wfg@mail.ustc.edu.cn>
      Cc: Michael Rubin <mrubin@google.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8bc3be27
    • H
      mm: remove fastcall from mm/ · 920c7a5d
      Harvey Harrison 提交于
      fastcall is always defined to be empty, remove it
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      920c7a5d
    • B
      mm/page-writeback: highmem_is_dirtyable option · 195cf453
      Bron Gondwana 提交于
      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: NBron Gondwana <brong@fastmail.fm>
      Cc: Ethan Solomita <solo@google.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: WU Fengguang <wfg@mail.ustc.edu.cn>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      195cf453
    • A
      mm/page-writeback.c: make a function static · f61eaf9f
      Adrian Bunk 提交于
      task_dirty_limit() can become static.
      Signed-off-by: NAdrian Bunk <bunk@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f61eaf9f
  11. 15 1月, 2008 1 次提交
  12. 16 11月, 2007 1 次提交
    • L
      dirty page balancing: Get rid of broken unmapped_ratio logic · 8c086340
      Linus Torvalds 提交于
      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: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8c086340
  13. 15 11月, 2007 1 次提交
  14. 20 10月, 2007 1 次提交
  15. 17 10月, 2007 10 次提交
  16. 09 10月, 2007 1 次提交
  17. 20 7月, 2007 3 次提交
    • A
      move page writeback acounting out of macros · d688abf5
      Andrew Morton 提交于
      page-writeback accounting is presently performed in the page-flags macros.
      This is inconsistent and a bit ugly and makes it awkward to implement
      per-backing_dev under-writeback page accounting.
      
      So move this accounting down to the callsite(s).
      Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d688abf5
    • F
      mm: share PG_readahead and PG_reclaim · fe3cba17
      Fengguang Wu 提交于
      Share the same page flag bit for PG_readahead and PG_reclaim.
      
      One is used only on file reads, another is only for emergency writes.  One
      is used mostly for fresh/young pages, another is for old pages.
      
      Combinations of possible interactions are:
      
      a) clear PG_reclaim => implicit clear of PG_readahead
      	it will delay an asynchronous readahead into a synchronous one
      	it actually does _good_ for readahead:
      		the pages will be reclaimed soon, it's readahead thrashing!
      		in this case, synchronous readahead makes more sense.
      
      b) clear PG_readahead => implicit clear of PG_reclaim
      	one(and only one) page will not be reclaimed in time
      	it can be avoided by checking PageWriteback(page) in readahead first
      
      c) set PG_reclaim => implicit set of PG_readahead
      	will confuse readahead and make it restart the size rampup process
      	it's a trivial problem, and can mostly be avoided by checking
      	PageWriteback(page) first in readahead
      
      d) set PG_readahead => implicit set of PG_reclaim
      	PG_readahead will never be set on already cached pages.
      	PG_reclaim will always be cleared on dirtying a page.
      	so not a problem.
      
      In summary,
      	a)   we get better behavior
      	b,d) possible interactions can be avoided
      	c)   racy condition exists that might affect readahead, but the chance
      	     is _really_ low, and the hurt on readahead is trivial.
      
      Compound pages also use PG_reclaim, but for now they do not interact with
      reclaim/readahead code.
      Signed-off-by: NFengguang Wu <wfg@mail.ustc.edu.cn>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      fe3cba17
    • N
      mm: fix clear_page_dirty_for_io vs fault race · 79352894
      Nick Piggin 提交于
      Fix msync data loss and (less importantly) dirty page accounting
      inaccuracies due to the race remaining in clear_page_dirty_for_io().
      
      The deleted comment explains what the race was, and the added comments
      explain how it is fixed.
      Signed-off-by: NNick Piggin <npiggin@suse.de>
      Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
      Cc: Miklos Szeredi <miklos@szeredi.hu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      79352894
  18. 18 7月, 2007 1 次提交
    • N
      fs: introduce some page/buffer invariants · 787d2214
      Nick Piggin 提交于
      It is a bug to set a page dirty if it is not uptodate unless it has
      buffers.  If the page has buffers, then the page may be dirty (some buffers
      dirty) but not uptodate (some buffers not uptodate).  The exception to this
      rule is if the set_page_dirty caller is racing with truncate or invalidate.
      
      A buffer can not be set dirty if it is not uptodate.
      
      If either of these situations occurs, it indicates there could be some data
      loss problem.  Some of these warnings could be a harmless one where the
      page or buffer is set uptodate immediately after it is dirtied, however we
      should fix those up, and enforce this ordering.
      
      Bring the order of operations for truncate into line with those of
      invalidate.  This will prevent a page from being able to go !uptodate while
      we're holding the tree_lock, which is probably a good thing anyway.
      Signed-off-by: NNick Piggin <npiggin@suse.de>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      787d2214
  19. 17 7月, 2007 1 次提交
  20. 11 5月, 2007 1 次提交
  21. 09 5月, 2007 1 次提交