Re: Freeing vnodes.

From: Jeff Roberson (jroberson_at_chesapeake.net)
Date: 03/15/05

  • Next message: Matthew Dillon: "Re: Freeing vnodes." 
    Date: Tue, 15 Mar 2005 00:39:33 -0500 (EST)
To: Stephan Uphoff <ups@tree.com>

    On Mon, 14 Mar 2005, Stephan Uphoff wrote:

    > On Mon, 2005-03-14 at 21:38, Jeff Roberson wrote:
    > > I have a patch at http://www.chesapeake.net/~jroberson/freevnodes.diff
    > > that allows us to start reclaiming vnodes from the free list and release
    > > their memory. It also changes the semantics of wantfreevnodes, and makes
    > > getnewvnode() much prettier.
    > >
    > > The changes attempt to keep some number of vnodes, currently 2.5% of
    > > desiredvnodes, that are free in memory. Free vnodes are vnodes which
    > > have no references or pages in memory. For example, if an application
    > > simply stat's a vnode, it will end up on the free list at the end of the
    > > operation. The algorithm that is currently in place will immediately
    > > recycle these vnodes once there is enough pressure, which will cause us to
    > > do a full lookup and reread the inode, etc. as soon as it is stat'd again.
    > >
    > > This also removes the recycling from the getnewvnode() path. Instead, it
    > > is done by a new helper function that is called from vnlru_proc(). This
    > > function just frees vnodes from the head of the list until we reach our
    > > wantfreevnodes target.
    > >
    > > I haven't perf tested this yet, but I have a box that is doing a
    > > buildworld with a fairly constant freevnodes count which shows that vnodes
    > > are actually being uma_zfree'd.
    > >
    > > Comments? Anyone willing to do some perf tests for me?
    > >
    > > Thanks,
    > > Jeff
    >
    > Just looked at the raw diff and might have missed it - how are the
    > parent directory "name" cache entries ( vnode fields v_dd, v_ddid)
    > handled?

    Just as they were before, by calling cache_purge.

    >
    > Thanks,
    > Stephan
    >
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  • Next message: Matthew Dillon: "Re: Freeing vnodes."

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