• Eric Dumazet's avatar
    [PATCH] dcache: avoid RCU for never-hashed dentries · b3423415
    Eric Dumazet authored
    Some dentries don't need to be globally visible in dentry hashtable.
    (pipes & sockets)
    
    Such dentries dont need to wait for a RCU grace period at delete time.
    Being able to free them permits a better CPU cache use (hot cache)
    
    This patch combined with (dont insert pipe dentries into dentry_hashtable)
    reduced time of { pipe(p); close(p[0]); close(p[1]);} on my UP machine (1.6
    GHz Pentium-M) from 3.23 us to 2.86 us (But this patch does not depend on
    other patches, only bench results)
    Signed-off-by: default avatarEric Dumazet <dada1@cosmosbay.com>
    Cc: Al Viro <viro@zeniv.linux.org.uk>
    Cc: Maneesh Soni <maneesh@in.ibm.com>
    Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
    Cc: Dipankar Sarma <dipankar@in.ibm.com>
    Acked-by: default avatarDavid Miller <davem@davemloft.net>
    Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
    b3423415
dcache.c 53.8 KB