• Bob Peterson's avatar
    GFS2: Instruct DLM to avoid queue convert slowdown · 4c569a72
    Bob Peterson authored
    This patch instructs DLM to prevent an "in place" conversion, where the
    lock just stays on the granted queue, and instead forces the conversion to
    the back of the convert queue. This is done on upward conversions only.
        
    This is useful in cases where, for example, a lock is frequently needed in
    PR on one node, but another node needs it temporarily in EX to update it.
    This may happen, for example, when the rindex is being updated by gfs2_grow.
    The gfs2_grow needs to have the lock in EX, but the other nodes need to
    re-read it to retrieve the updates. The glock is already granted in PR on
    the non-growing nodes, so this prevents them from continually re-granting
    the lock in PR, and forces the EX from gfs2_grow to go through.
    Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
    Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
    4c569a72
lock_dlm.c 38.3 KB