lkml.org 
[lkml]   [2010]   [Feb]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Subject[PATCH v2 00/18] Increase maximum number of Infiniband HCAs per system
    From
    Date
    This is v2 of a patch series that increases the maximum number of
    IB HCAs supported per system.

    The original mail thread is here:
    http://lkml.org/lkml/2010/1/29/346

    One note, I decided to "copy/paste" since factoring out the overflow
    code in the three drivers seemed like overkill. If so desired, I could
    factor those three separate functions into something provided by the
    core, but that seemed like more trouble than it was worth at the time.

    As before, I still don't have access to a giant system, so what I did
    to test was to stick 4 cards into a small system, and then modify the
    limits with debug patches similar to this:

    diff --git a/drivers/infiniband/core/ucm.c b/drivers/infiniband/core/ucm.c
    index 7bf0a82..8581e64 100644
    --- a/drivers/infiniband/core/ucm.c
    +++ b/drivers/infiniband/core/ucm.c
    @@ -102,7 +102,7 @@ struct ib_ucm_event {
    enum {
    IB_UCM_MAJOR = 231,
    IB_UCM_BASE_MINOR = 224,
    - IB_UCM_MAX_DEVICES = 32
    + IB_UCM_MAX_DEVICES = 2
    };


    I tested all 3 drivers this way (uverbs, umad, ucm). I verified that
    we're not leaking device numbers on multiple modprobe/rmmod cycles,
    that there aren't any funny interactions when various combinations of
    the drivers are loaded.
    I did not test the rest of the OFED stack. I did write some trivial
    programs to open the devices in /dev and close them again.

    Here's an example of some of the testing:

    dl585g2:~ # modprobe ib_uverbs
    dl585g2:~ # modprobe ib_umad
    dl585g2:~ # modprobe ib_ucm
    dl585g2:~ # ls -l /dev/uverb*
    crw-rw---- 1 root root 231, 192 Feb 2 05:55 /dev/uverbs0
    crw-rw---- 1 root root 231, 193 Feb 2 05:55 /dev/uverbs1
    crw-rw---- 1 root root 249, 0 Feb 2 05:55 /dev/uverbs2
    crw-rw---- 1 root root 249, 1 Feb 2 05:55 /dev/uverbs3
    dl585g2:~ # ls -l /dev/umad*
    crw-rw---- 1 root root 231, 0 Feb 2 05:55 /dev/umad0
    crw-rw---- 1 root root 231, 1 Feb 2 05:55 /dev/umad1
    crw-rw---- 1 root root 231, 2 Feb 2 05:55 /dev/umad2
    crw-rw---- 1 root root 231, 3 Feb 2 05:55 /dev/umad3
    crw-rw---- 1 root root 248, 0 Feb 2 05:55 /dev/umad4
    crw-rw---- 1 root root 248, 1 Feb 2 05:55 /dev/umad5
    crw-rw---- 1 root root 248, 2 Feb 2 05:55 /dev/umad6
    crw-rw---- 1 root root 248, 3 Feb 2 05:55 /dev/umad7
    dl585g2:~ # ls -l /dev/issm*
    crw-rw---- 1 root root 231, 4 Feb 2 05:55 /dev/issm0
    crw-rw---- 1 root root 231, 5 Feb 2 05:55 /dev/issm1
    crw-rw---- 1 root root 231, 6 Feb 2 05:55 /dev/issm2
    crw-rw---- 1 root root 231, 7 Feb 2 05:55 /dev/issm3
    crw-rw---- 1 root root 248, 4 Feb 2 05:55 /dev/issm4
    crw-rw---- 1 root root 248, 5 Feb 2 05:55 /dev/issm5
    crw-rw---- 1 root root 248, 6 Feb 2 05:55 /dev/issm6
    crw-rw---- 1 root root 248, 7 Feb 2 05:55 /dev/issm7
    dl585g2:~ # ls -l /dev/ucm*
    crw-rw---- 1 root root 231, 224 Feb 2 05:55 /dev/ucm0
    crw-rw---- 1 root root 231, 225 Feb 2 05:55 /dev/ucm1
    crw-rw---- 1 root root 247, 0 Feb 2 05:55 /dev/ucm2
    crw-rw---- 1 root root 247, 1 Feb 2 05:55 /dev/ucm3
    Note that the major and minor numbers are behaving rather sanely.

    dl585g2:~ # rmmod ib_ucm
    dl585g2:~ # rmmod ib_uverbs
    dl585g2:~ # rmmod ib_umad

    Reset.

    dl585g2:~ # modprobe ib_ucm
    dl585g2:~ # ls -l /dev/ucm*
    crw-rw---- 1 root root 231, 224 Feb 2 05:57 /dev/ucm0
    crw-rw---- 1 root root 231, 225 Feb 2 05:57 /dev/ucm1
    crw-rw---- 1 root root 248, 0 Feb 2 05:57 /dev/ucm2
    crw-rw---- 1 root root 248, 1 Feb 2 05:57 /dev/ucm3
    See that /dev/ucm* devices now have a different major number
    compared to last time(248 vs 247), since we loaded that driver first.

    But wait, why is it 248 and not 249? Is there a leak somewhere?

    dl585g2:~ # ls -l /dev/uverb*
    crw-rw---- 1 root root 231, 192 Feb 2 05:57 /dev/uverbs0
    crw-rw---- 1 root root 231, 193 Feb 2 05:57 /dev/uverbs1
    crw-rw---- 1 root root 249, 0 Feb 2 05:57 /dev/uverbs2
    crw-rw---- 1 root root 249, 1 Feb 2 05:57 /dev/uverbs3
    dl585g2:~ # rmmod ib_uverbs
    ERROR: Module ib_uverbs is in use by ib_ucm
    Ah, ib_ucm is dependent on ib_uverbs, so when we modprobed ib_ucm,
    in reality ib_uverbs got loaded first. See how it has a higher
    major number.

    dl585g2:~ # rmmod ib_ucm
    dl585g2:~ # rmmod ib_uverbs
    dl585g2:~ # modprobe ib_umad
    dl585g2:~ # ls -l /dev/umad*
    crw-rw---- 1 root root 231, 0 Feb 2 05:58 /dev/umad0
    crw-rw---- 1 root root 231, 1 Feb 2 05:58 /dev/umad1
    crw-rw---- 1 root root 231, 2 Feb 2 05:58 /dev/umad2
    crw-rw---- 1 root root 231, 3 Feb 2 05:58 /dev/umad3
    crw-rw---- 1 root root 249, 0 Feb 2 05:58 /dev/umad4
    crw-rw---- 1 root root 249, 1 Feb 2 05:58 /dev/umad5
    crw-rw---- 1 root root 249, 2 Feb 2 05:58 /dev/umad6
    crw-rw---- 1 root root 249, 3 Feb 2 05:58 /dev/umad7
    dl585g2:~ # ls -l /dev/issm*
    crw-rw---- 1 root root 231, 4 Feb 2 05:58 /dev/issm0
    crw-rw---- 1 root root 231, 5 Feb 2 05:58 /dev/issm1
    crw-rw---- 1 root root 231, 6 Feb 2 05:58 /dev/issm2
    crw-rw---- 1 root root 231, 7 Feb 2 05:58 /dev/issm3
    crw-rw---- 1 root root 249, 4 Feb 2 05:58 /dev/issm4
    crw-rw---- 1 root root 249, 5 Feb 2 05:58 /dev/issm5
    crw-rw---- 1 root root 249, 6 Feb 2 05:58 /dev/issm6
    crw-rw---- 1 root root 249, 7 Feb 2 05:58 /dev/issm7
    Finally, after one more reset, we see ib_umad loaded first and
    obtaining the major number of 249.

    v1 -> v2:
    - update umad and ucm drivers too

    ---
    Alex Chiang (18):
    IB/uverbs: convert *cdev to cdev in struct ib_uverbs_device
    IB/uverbs: remove dev_table
    IB/uverbs: use stack variable 'devnum' in ib_uverbs_add_one
    IB/uverbs: use stack variable 'base' in ib_uverbs_add_one
    IB/uverbs: increase maximum devices supported
    IB/uverbs: pack struct ib_uverbs_event_file tighter
    IB/uverbs: whitespace cleanup
    IB/umad: convert cdev pointers to embedded structs in struct ib_umad_port
    IB/umad: remove port_table[]
    IB/umad: use stack variable 'devnum' in ib_umad_init_port
    IB/umad: use stack variable 'base' in ib_umad_init_port
    IB/umad: increase maximum devices supported
    IB/umad: clean whitespace
    IB/ucm: use stack variable 'devnum' in ib_ucm_add_one
    IB/ucm: use stack variable 'base' in ib_ucm_add_one
    IB/ucm: increase maximum devices supported
    IB/ucm: clean whitespace errors
    IB/core: pack struct ib_device a little tighter


    drivers/infiniband/core/ucm.c | 63 ++++++++++--
    drivers/infiniband/core/user_mad.c | 173 +++++++++++++++++----------------
    drivers/infiniband/core/uverbs.h | 11 +-
    drivers/infiniband/core/uverbs_main.c | 175 +++++++++++++++++++--------------
    include/rdma/ib_verbs.h | 4 -
    5 files changed, 255 insertions(+), 171 deletions(-)


    \
     
     \ /
      Last update: 2010-02-02 20:09    [W:4.517 / U:0.180 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site