• Eric Van Hensbergen's avatar
    9p: implement optional loose read cache · e03abc0c
    Eric Van Hensbergen authored
    While cacheing is generally frowned upon in the 9p world, it has its
    place -- particularly in situations where the remote file system is
    exclusive and/or read-only.  The vacfs views of venti content addressable
    store are a real-world instance of such a situation.  To facilitate higher
    performance for these workloads (and eventually use the fscache patches),
    we have enabled a "loose" cache mode which does not attempt to maintain
    any form of consistency on the page-cache or dcache.  This results in over
    two orders of magnitude performance improvement for cacheable block reads
    in the Bonnie benchmark.  The more aggressive use of the dcache also seems
    to improve metadata operational performance.
    Signed-off-by: default avatarEric Van Hensbergen <ericvh@gmail.com>