• Jens Axboe's avatar
    aio: make the lookup_ioctx() lockless · abf137dd
    Jens Axboe authored
    The mm->ioctx_list is currently protected by a reader-writer lock,
    so we always grab that lock on the read side for doing ioctx
    lookups. As the workload is extremely reader biased, turn this into
    an rcu hlist so we can make lookup_ioctx() lockless. Get rid of
    the rwlock and use a spinlock for providing update side exclusion.
    There's usually only 1 entry on this list, so it doesn't make sense
    to look into fancier data structures.
    Reviewed-by: default avatarJeff Moyer <jmoyer@redhat.com>
    Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
fork.c 41.2 KB