RE: [PATCH 1/2] rdma/cm: support option to allow manually setting IB path

Sean Hefty
2009-10-09T21:48:03Z

Before spending any more time on this patch series, is there any disagreement to
accepting this patch (as is or slightly modified) upstream?

- Sean

>Export rdma_set_ib_paths to user space to allow applications to
>manually set the IB path used for connections. This allows
>alternative ways for a user space application or library to obtain
>path record information, including retrieving path information
>from cached data, avoiding direct interaction with the IB SA.
>The IB SA is a single, centralized entity that can limit scaling
>on large clusters running MPI applications.
>
>Signed-off-by: Sean Hefty <sean.hefty-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
>---
>I'd like to get feedback on this approach with the possibility of merging
>for 2.6.33.
>
> drivers/infiniband/core/ucma.c | 40 ++++++++++++++++++++++++++++++++++++++++
> include/rdma/rdma_user_cm.h | 7 +++++--
> 2 files changed, 45 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
>index 4346a24..1359727 100644
>--- a/drivers/infiniband/core/ucma.c
>+++ b/drivers/infiniband/core/ucma.c
>@@ -42,6 +42,7 @@
> #include <rdma/rdma_user_cm.h>
> #include <rdma/ib_marshall.h>
> #include <rdma/rdma_cm.h>
>+#include <rdma/rdma_cm_ib.h>
>
> MODULE_AUTHOR("Sean Hefty");
> MODULE_DESCRIPTION("RDMA Userspace Connection Manager Access");
>@@ -811,6 +812,42 @@ static int ucma_set_option_id(struct ucma_context *ctx,
>int optname,
> return ret;
> }
>
>+static int ucma_set_ib_path(struct ucma_context *ctx,
>+ struct ib_user_path_rec *upath, size_t optlen)
>+{
>+ struct ib_sa_path_rec sa_path;
>+ struct rdma_cm_event event;
>+ int ret;
>+
>+ if (optlen != sizeof(*upath))
>+ return -EINVAL;
>+
>+ ib_copy_path_rec_from_user(&sa_path, upath);
>+ ret = rdma_set_ib_paths(ctx->cm_id, &sa_path, 1);
>+ if (ret)
>+ return ret;
>+
>+ memset(&event, 0, sizeof event);
>+ event.event = RDMA_CM_EVENT_ROUTE_RESOLVED;
>+ return ucma_event_handler(ctx->cm_id, &event);
>+}
>+
>+static int ucma_set_option_ib(struct ucma_context *ctx, int optname,
>+ void *optval, size_t optlen)
>+{
>+ int ret;
>+
>+ switch (optname) {
>+ case RDMA_OPTION_IB_PATH:
>+ ret = ucma_set_ib_path(ctx, optval, optlen);
>+ break;
>+ default:
>+ ret = -ENOSYS;
>+ }
>+
>+ return ret;
>+}
>+
> static int ucma_set_option_level(struct ucma_context *ctx, int level,
> int optname, void *optval, size_t optlen)
> {
>@@ -820,6 +857,9 @@ static int ucma_set_option_level(struct ucma_context *ctx,
>int level,
> case RDMA_OPTION_ID:
> ret = ucma_set_option_id(ctx, optname, optval, optlen);
> break;
>+ case RDMA_OPTION_IB:
>+ ret = ucma_set_option_ib(ctx, optname, optval, optlen);
>+ break;
> default:
> ret = -ENOSYS;
> }
>diff --git a/include/rdma/rdma_user_cm.h b/include/rdma/rdma_user_cm.h
>index c557054..d7829f4 100644
>--- a/include/rdma/rdma_user_cm.h
>+++ b/include/rdma/rdma_user_cm.h
>@@ -215,12 +215,15 @@ struct rdma_ucm_event_resp {
>
> /* Option levels */
> enum {
>- RDMA_OPTION_ID = 0
>+ RDMA_OPTION_ID = 0,
>+ RDMA_OPTION_IB = 1
> };
>
> /* Option details */
> enum {
>- RDMA_OPTION_ID_TOS = 0
>+ RDMA_OPTION_ID_TOS = 0,
>+
>+ RDMA_OPTION_IB_PATH = 1
> };
>
> struct rdma_ucm_set_option {
>
>