lkml.org 
[lkml]   [2014]   [Dec]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [dm-devel] [PATCH] staging: writeboost: Add dm-writeboost
    On Wed, Dec 10, 2014 at 09:59:12PM +0900, Akira Hayakawa wrote:
    > Joe,
    >
    > I appreciate your continuous work.
    >
    > Is that read or write?
    > The difference between Type 0 and 1 should only show up in write path.
    > So is it write test?

    Yes, writing across the whole device using 'dd'.

    These are the tests:

    dmtest list --suite writeboost -n /wipe_device/

    > And what is the unit of each result?

    seconds.

    >
    > > So maybe it's just volume of IO that's causing the problem? What's
    > > the difference between Type 0 and Type 1? In the code I notice you
    > > have 'rambuf' structures, are you caching IO in memory?
    > "rambuf" is a temporary space that every write data comes in.
    > 127*4KB data are once stored there and 4KB metadata section are added
    > then it becomes a log and flushed to the cache device sequentially (512KB each).

    So you copy the bio payload to a different block of ram and then
    complete the bio? Or does the rambuf refer to the bio payload
    directly?

    > By the way,
    > I think more clearer discussion can be done if tests are done on physical machines
    > to isolate things relevant to VM. I will also add these tests to dmts later and
    > run on my machine.
    > But, it will be much better if we have good server with RAID-ed backing store
    > and the newest SSD (How would it be if it's PCI-e SSD)...

    I generally find it quicker to investigate problems on the machine
    that are actually exhibiting the problem ;) Seriously though, you're
    asking us to send this upstream; it needs to work on consumer level
    hardware.

    I've got a big machine with Fusion IO storage that I can run the same
    tests on later.

    - Joe


    \
     
     \ /
      Last update: 2014-12-10 14:41    [W:2.306 / U:0.024 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site