09 Dec, 2006

1 commit


09 Jan, 2006

1 commit

  • Some long time ago, dentry struct was carefully tuned so that on 32 bits
    UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple
    of memory cache lines.

    Then RCU was added and dentry struct enlarged by two pointers, with nice
    results for SMP, but not so good on UP, because breaking the above tuning
    (128 + 8 = 136 bytes)

    This patch reverts this unwanted side effect, by using an union (d_u),
    where d_rcu and d_child are placed so that these two fields can share their
    memory needs.

    At the time d_free() is called (and d_rcu is really used), d_child is known
    to be empty and not touched by the dentry freeing.

    Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so
    the previous content of d_child is not needed if said dentry was unhashed
    but still accessed by a CPU because of RCU constraints)

    As dentry cache easily contains millions of entries, a size reduction is
    worth the extra complexity of the ugly C union.

    Signed-off-by: Eric Dumazet
    Cc: Dipankar Sarma
    Cc: Maneesh Soni
    Cc: Miklos Szeredi
    Cc: "Paul E. McKenney"
    Cc: Ian Kent
    Cc: Paul Jackson
    Cc: Al Viro
    Cc: Christoph Hellwig
    Cc: Trond Myklebust
    Cc: Neil Brown
    Cc: James Morris
    Cc: Stephen Smalley
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Eric Dumazet
     

17 Apr, 2005

1 commit

  • Initial git repository build. I'm not bothering with the full history,
    even though we have it. We can create a separate "historical" git
    archive of that later if we want to, and in the meantime it's about
    3.2GB when imported into git - space that would just make the early
    git days unnecessarily complicated, when we don't have a lot of good
    infrastructure for it.

    Let it rip!

    Linus Torvalds