24 Sep, 2009

1 commit

  • It's unused.

    It isn't needed -- read or write flag is already passed and sysctl
    shouldn't care about the rest.

    It _was_ used in two places at arch/frv for some reason.

    Signed-off-by: Alexey Dobriyan
    Cc: David Howells
    Cc: "Eric W. Biederman"
    Cc: Al Viro
    Cc: Ralf Baechle
    Cc: Martin Schwidefsky
    Cc: Ingo Molnar
    Cc: "David S. Miller"
    Cc: James Morris
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Alexey Dobriyan
     

17 Jun, 2009

1 commit

  • Remove __invalidate_mapping_pages atomic variant now that its sole caller
    can sleep (fixed in eccb95cee4f0d56faa46ef22fb94dd4a3578d3eb ("vfs: fix
    lock inversion in drop_pagecache_sb()")).

    This fixes softlockups that can occur while in the drop_caches path.

    Signed-off-by: Mike Waychison
    Cc: Jan Kara
    Cc: Wu Fengguang
    Cc: Dave Chinner
    Cc: Nick Piggin
    Acked-by: Jan Kara
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mike Waychison
     

03 Apr, 2009

1 commit

  • clear_inode() will switch inode state from I_FREEING to I_CLEAR, and do so
    _outside_ of inode_lock. So any I_FREEING testing is incomplete without a
    coupled testing of I_CLEAR.

    So add I_CLEAR tests to drop_pagecache_sb(), generic_sync_sb_inodes() and
    add_dquot_ref().

    Masayoshi MIZUMA discovered the bug in drop_pagecache_sb() and Jan Kara
    reminds fixing the other two cases.

    Masayoshi MIZUMA has a nice panic flow:

    =====================================================================
    [process A] | [process B]
    | |
    | prune_icache() | drop_pagecache()
    | spin_lock(&inode_lock) | drop_pagecache_sb()
    | inode->i_state |= I_FREEING; | |
    | spin_unlock(&inode_lock) | V
    | | | spin_lock(&inode_lock)
    | V | |
    | dispose_list() | |
    | list_del() | |
    | clear_inode() | |
    | inode->i_state = I_CLEAR | |
    | | | V
    | | | if (inode->i_state & (I_FREEING|I_WILL_FREE))
    | | | continue;
    Reviewed-by: Jan Kara
    Signed-off-by: Wu Fengguang
    Cc:
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Wu Fengguang
     

28 Mar, 2009

1 commit

  • To be on the safe side, it should be less fragile to exclude I_NEW inodes
    from inode list scans by default (unless there is an important reason to
    have them).

    Normally they will get excluded (eg. by zero refcount or writecount etc),
    however it is a bit fragile for list walkers to know exactly what parts of
    the inode state is set up and valid to test when in I_NEW. So along these
    lines, move I_NEW checks upward as well (sometimes taking I_FREEING etc
    checks with them too -- this shouldn't be a problem should it?)

    Signed-off-by: Nick Piggin
    Acked-by: Jan Kara
    Cc: Al Viro
    Signed-off-by: Andrew Morton
    Signed-off-by: Al Viro

    Nick Piggin
     

29 Apr, 2008

3 commits


17 Jul, 2007

1 commit

  • invalidate_mapping_pages() can sometimes take a long time (millions of pages
    to free). Long enough for the softlockup detector to trigger.

    We used to have a cond_resched() in there but I took it out because the
    drop_caches code calls invalidate_mapping_pages() under inode_lock.

    The patch adds a nasty flag and puts the cond_resched() back.

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

    Andrew Morton
     

12 Feb, 2007

1 commit


09 Jan, 2006

1 commit

  • Add /proc/sys/vm/drop_caches. When written to, this will cause the kernel to
    discard as much pagecache and/or reclaimable slab objects as it can. THis
    operation requires root permissions.

    It won't drop dirty data, so the user should run `sync' first.

    Caveats:

    a) Holds inode_lock for exorbitant amounts of time.

    b) Needs to be taught about NUMA nodes: propagate these all the way through
    so the discarding can be controlled on a per-node basis.

    This is a debugging feature: useful for getting consistent results between
    filesystem benchmarks. We could possibly put it under a config option, but
    it's less than 300 bytes.

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

    Andrew Morton