Re: [PATCH for-next] RDMA/rxe: Fix freeing busy objects

[Zhu Yanjun <yanjun.zhu@xxxxxxxxx>]

在 2023/7/1 22:48, Bob Pearson 写道:
> On 7/1/23 01:50, Zhu Yanjun wrote:
> > 在 2023/7/1 0:38, Bob Pearson 写道:
> > > Currently the rxe driver calls wait_for_completion_timeout() in
> > > rxe_complete() to wait until all the references to the object have
> > > been freed before final cleanup and returning to the rdma-core
> > > destroy verb. If this does not happen within the timeout interval
> > > it prints a WARN_ON and returns to the 'destroy' verb caller
> > > without any indication that there was an error. This is incorrect.
> > >
> > > A very heavily loaded system can take an arbitrarily long time to
> > > complete the work needed before freeing all the references with no
> > > guarantees of performance within a specific time. This has been
> > > observed in high stress high scale testing of the rxe driver.
> > >
> > > Another frequent cause of these timeouts is due to ref counting bugs
> > > introduced by changes in the driver so it is helpful to continue
> > > to report the timeouts.
> > >
> > > This patch puts the completion timeout call in a loop with a 10 second
> > > timeout and issues a WARN_ON each pass through the loop. The case
> > > for objects that cannot sleep is treated similarly. It also changes
> > > the type of the rxe_cleanup() subroutine to void and fixes calls to
> > > reflect this API change. This is better aligned with the code in
> > > rdma-core which sometimes fails to check the return value of
> > > destroy verb calls assuming they will always succeed. Specifically
> > > this is the case for kernel qp's.
> > Hi, Bob
> >
> > You change the timeout to 10s in this commit. Based on https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes
> >
> > Can you describe the pros and cons of this change?
> > If there are some data to support your change, it is better.
> The problem is that a heavily loaded system can take a long time to complete work.
> This is not a bug per se so it would be wrong to terminate IO in progress. But on the
> other hand it is most likely not going to recover so it helps to report the condition.
> This patch replaces an error exit with a wait as long as necessary, or until someone
> intervenes and reboots the system. The previous timeout code issued a WARN_ON in about
> 0.2 seconds and then exiting leaving a messy situation that wasn't going to get fixed.
> The new version issues a WARN_ON every 10 seconds until the operation succeeds or
> the system is rebooted. This is long enough that is won't clog the logs but often enough
> to get noticed.


To fix this problem, you changes too much.

I received the trainings from different companies. In the trainings,  an 
important code conduct is: modify the minimum source codes to fix a problem.

Too much changes will introduce risks. This is to a commericial software 
products. I am not sure whether it is good to an open source project or not.

And if we need to changes too much, according to 
https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes, 
it had better split the big commit to several commits.

One commit is to fix one problem.

Just my 2 cents.

Zhu Yanjun

> If rdma-core handled error returns from ib_destroy_qp correctly a cleaner solution might
> be possible but it doesn't. This approach is similar to the soft lockup warnings from Linux.
>
> This change is a result of very high load stress testing causing the current version to fail.
>
> Bob
> > Thanks
> > Zhu Yanjun
> >
> > > Fixes: 215d0a755e1b ("RDMA/rxe: Stop lookup of partially built objects")
> > > Signed-off-by: Bob Pearson <rpearsonhpe@xxxxxxxxx>
> > > ---
> > >    drivers/infiniband/sw/rxe/rxe_pool.c  |  39 ++++------
> > >    drivers/infiniband/sw/rxe/rxe_pool.h  |   2 +-
> > >    drivers/infiniband/sw/rxe/rxe_verbs.c | 108 ++++++++++----------------
> > >    3 files changed, 56 insertions(+), 93 deletions(-)
> > >
> > > diff --git a/drivers/infiniband/sw/rxe/rxe_pool.c b/drivers/infiniband/sw/rxe/rxe_pool.c
> > > index 6215c6de3a84..819dc30a7a96 100644
> > > --- a/drivers/infiniband/sw/rxe/rxe_pool.c
> > > +++ b/drivers/infiniband/sw/rxe/rxe_pool.c
> > > @@ -6,7 +6,7 @@
> > >      #include "rxe.h"
> > >    -#define RXE_POOL_TIMEOUT    (200)
> > > +#define RXE_POOL_TIMEOUT    (10000)    /* 10 seconds */
> > >    #define RXE_POOL_ALIGN        (16)
> > >      static const struct rxe_type_info {
> > > @@ -171,15 +171,16 @@ static void rxe_elem_release(struct kref *kref)
> > >    {
> > >        struct rxe_pool_elem *elem = container_of(kref, typeof(*elem), ref_cnt);
> > >    -    complete(&elem->complete);
> > > +    complete_all(&elem->complete);
> > >    }
> > >    -int __rxe_cleanup(struct rxe_pool_elem *elem, bool sleepable)
> > > +void __rxe_cleanup(struct rxe_pool_elem *elem, bool sleepable)
> > >    {
> > >        struct rxe_pool *pool = elem->pool;
> > >        struct xarray *xa = &pool->xa;
> > > -    static int timeout = RXE_POOL_TIMEOUT;
> > > -    int ret, err = 0;
> > > +    int timeout = RXE_POOL_TIMEOUT;
> > > +    unsigned long until;
> > > +    int ret;
> > >        void *xa_ret;
> > >          if (sleepable)
> > > @@ -202,39 +203,31 @@ int __rxe_cleanup(struct rxe_pool_elem *elem, bool sleepable)
> > >         * return to rdma-core
> > >         */
> > >        if (sleepable) {
> > > -        if (!completion_done(&elem->complete) && timeout) {
> > > +        while (!completion_done(&elem->complete) && timeout) {
> > >                ret = wait_for_completion_timeout(&elem->complete,
> > >                        timeout);
> > > -
> > > -            /* Shouldn't happen. There are still references to
> > > -             * the object but, rather than deadlock, free the
> > > -             * object or pass back to rdma-core.
> > > -             */
> > > -            if (WARN_ON(!ret))
> > > -                err = -EINVAL;
> > > +            WARN_ON(!ret);
> > >            }
> > >        } else {
> > > -        unsigned long until = jiffies + timeout;
> > > -
> > >            /* AH objects are unique in that the destroy_ah verb
> > >             * can be called in atomic context. This delay
> > >             * replaces the wait_for_completion call above
> > >             * when the destroy_ah call is not sleepable
> > >             */
> > > -        while (!completion_done(&elem->complete) &&
> > > -                time_before(jiffies, until))
> > > -            mdelay(1);
> > > -
> > > -        if (WARN_ON(!completion_done(&elem->complete)))
> > > -            err = -EINVAL;
> > > +        while (!completion_done(&elem->complete) && timeout) {
> > > +            until = jiffies + timeout;
> > > +            while (!completion_done(&elem->complete) &&
> > > +                   time_before(jiffies, until)) {
> > > +                mdelay(10);
> > > +            }
> > > +            WARN_ON(!completion_done(&elem->complete));
> > > +        }
> > >        }
> > >          if (pool->cleanup)
> > >            pool->cleanup(elem);
> > >          atomic_dec(&pool->num_elem);
> > > -
> > > -    return err;
> > >    }
> > >      int __rxe_get(struct rxe_pool_elem *elem)
> > > diff --git a/drivers/infiniband/sw/rxe/rxe_pool.h b/drivers/infiniband/sw/rxe/rxe_pool.h
> > > index b42e26427a70..14facdb45aad 100644
> > > --- a/drivers/infiniband/sw/rxe/rxe_pool.h
> > > +++ b/drivers/infiniband/sw/rxe/rxe_pool.h
> > > @@ -70,7 +70,7 @@ int __rxe_get(struct rxe_pool_elem *elem);
> > >    int __rxe_put(struct rxe_pool_elem *elem);
> > >    #define rxe_put(obj) __rxe_put(&(obj)->elem)
> > >    -int __rxe_cleanup(struct rxe_pool_elem *elem, bool sleepable);
> > > +void __rxe_cleanup(struct rxe_pool_elem *elem, bool sleepable);
> > >    #define rxe_cleanup(obj) __rxe_cleanup(&(obj)->elem, true)
> > >    #define rxe_cleanup_ah(obj, sleepable) __rxe_cleanup(&(obj)->elem, sleepable)
> > >    diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
> > > index f4321a172000..a5e639ee2217 100644
> > > --- a/drivers/infiniband/sw/rxe/rxe_verbs.c
> > > +++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
> > > @@ -218,11 +218,8 @@ static int rxe_alloc_ucontext(struct ib_ucontext *ibuc, struct ib_udata *udata)
> > >    static void rxe_dealloc_ucontext(struct ib_ucontext *ibuc)
> > >    {
> > >        struct rxe_ucontext *uc = to_ruc(ibuc);
> > > -    int err;
> > >    -    err = rxe_cleanup(uc);
> > > -    if (err)
> > > -        rxe_err_uc(uc, "cleanup failed, err = %d", err);
> > > +    rxe_cleanup(uc);
> > >    }
> > >      /* pd */
> > > @@ -248,11 +245,8 @@ static int rxe_alloc_pd(struct ib_pd *ibpd, struct ib_udata *udata)
> > >    static int rxe_dealloc_pd(struct ib_pd *ibpd, struct ib_udata *udata)
> > >    {
> > >        struct rxe_pd *pd = to_rpd(ibpd);
> > > -    int err;
> > >    -    err = rxe_cleanup(pd);
> > > -    if (err)
> > > -        rxe_err_pd(pd, "cleanup failed, err = %d", err);
> > > +    rxe_cleanup(pd);
> > >          return 0;
> > >    }
> > > @@ -265,7 +259,7 @@ static int rxe_create_ah(struct ib_ah *ibah,
> > >        struct rxe_dev *rxe = to_rdev(ibah->device);
> > >        struct rxe_ah *ah = to_rah(ibah);
> > >        struct rxe_create_ah_resp __user *uresp = NULL;
> > > -    int err, cleanup_err;
> > > +    int err;
> > >          if (udata) {
> > >            /* test if new user provider */
> > > @@ -312,9 +306,7 @@ static int rxe_create_ah(struct ib_ah *ibah,
> > >        return 0;
> > >      err_cleanup:
> > > -    cleanup_err = rxe_cleanup(ah);
> > > -    if (cleanup_err)
> > > -        rxe_err_ah(ah, "cleanup failed, err = %d", cleanup_err);
> > > +    rxe_cleanup(ah);
> > >    err_out:
> > >        rxe_err_ah(ah, "returned err = %d", err);
> > >        return err;
> > > @@ -354,11 +346,8 @@ static int rxe_query_ah(struct ib_ah *ibah, struct rdma_ah_attr *attr)
> > >    static int rxe_destroy_ah(struct ib_ah *ibah, u32 flags)
> > >    {
> > >        struct rxe_ah *ah = to_rah(ibah);
> > > -    int err;
> > >    -    err = rxe_cleanup_ah(ah, flags & RDMA_DESTROY_AH_SLEEPABLE);
> > > -    if (err)
> > > -        rxe_err_ah(ah, "cleanup failed, err = %d", err);
> > > +    rxe_cleanup_ah(ah, flags & RDMA_DESTROY_AH_SLEEPABLE);
> > >          return 0;
> > >    }
> > > @@ -371,12 +360,12 @@ static int rxe_create_srq(struct ib_srq *ibsrq, struct ib_srq_init_attr *init,
> > >        struct rxe_pd *pd = to_rpd(ibsrq->pd);
> > >        struct rxe_srq *srq = to_rsrq(ibsrq);
> > >        struct rxe_create_srq_resp __user *uresp = NULL;
> > > -    int err, cleanup_err;
> > > +    int err;
> > >          if (udata) {
> > >            if (udata->outlen < sizeof(*uresp)) {
> > >                err = -EINVAL;
> > > -            rxe_err_dev(rxe, "malformed udata");
> > > +            rxe_dbg_dev(rxe, "malformed udata");
> > >                goto err_out;
> > >            }
> > >            uresp = udata->outbuf;
> > > @@ -413,9 +402,7 @@ static int rxe_create_srq(struct ib_srq *ibsrq, struct ib_srq_init_attr *init,
> > >        return 0;
> > >      err_cleanup:
> > > -    cleanup_err = rxe_cleanup(srq);
> > > -    if (cleanup_err)
> > > -        rxe_err_srq(srq, "cleanup failed, err = %d", cleanup_err);
> > > +    rxe_cleanup(srq);
> > >    err_out:
> > >        rxe_err_dev(rxe, "returned err = %d", err);5f004bcaee4cb552cf1b46a50
> > >        return err;
> > > @@ -514,11 +501,8 @@ static int rxe_post_srq_recv(struct ib_srq *ibsrq, const struct ib_recv_wr *wr,
> > >    static int rxe_destroy_srq(struct ib_srq *ibsrq, struct ib_udata *udata)
> > >    {
> > >        struct rxe_srq *srq = to_rsrq(ibsrq);
> > > -    int err;
> > >    -    err = rxe_cleanup(srq);
> > > -    if (err)
> > > -        rxe_err_srq(srq, "cleanup failed, err = %d", err);
> > > +    rxe_cleanup(srq);
> > >          return 0;
> > >    }
> > > @@ -531,7 +515,7 @@ static int rxe_create_qp(struct ib_qp *ibqp, struct ib_qp_init_attr *init,
> > >        struct rxe_pd *pd = to_rpd(ibqp->pd);
> > >        struct rxe_qp *qp = to_rqp(ibqp);
> > >        struct rxe_create_qp_resp __user *uresp = NULL;
> > > -    int err, cleanup_err;
> > > +    int err;
> > >          if (udata) {
> > >            if (udata->inlen) {
> > > @@ -580,9 +564,7 @@ static int rxe_create_qp(struct ib_qp *ibqp, struct ib_qp_init_attr *init,
> > >        return 0;
> > >      err_cleanup:
> > > -    cleanup_err = rxe_cleanup(qp);
> > > -    if (cleanup_err)
> > > -        rxe_err_qp(qp, "cleanup failed, err = %d", cleanup_err);
> > > +    rxe_cleanup(qp);
> > >    err_out:
> > >        rxe_err_dev(rxe, "returned err = %d", err);
> > >        return err;
> > > @@ -648,9 +630,7 @@ static int rxe_destroy_qp(struct ib_qp *ibqp, struct ib_udata *udata)
> > >            goto err_out;
> > >        }
> > >    -    err = rxe_cleanup(qp);
> > > -    if (err)
> > > -        rxe_err_qp(qp, "cleanup failed, err = %d", err);
> > > +    rxe_cleanup(qp);
> > >          return 0;
> > >    @@ -675,12 +655,12 @@ static int validate_send_wr(struct rxe_qp *qp, const struct ib_send_wr *ibwr,
> > >        do {
> > >            mask = wr_opcode_mask(ibwr->opcode, qp);
> > >            if (!mask) {
> > > -            rxe_err_qp(qp, "bad wr opcode for qp type");
> > > +            rxe_dbg_qp(qp, "bad wr opcode for qp type");
> > >                break;
> > >            }
> > >              if (num_sge > sq->max_sge) {
> > > -            rxe_err_qp(qp, "num_sge > max_sge");
> > > +            rxe_dbg_qp(qp, "num_sge > max_sge");
> > >                break;
> > >            }
> > >    @@ -689,27 +669,27 @@ static int validate_send_wr(struct rxe_qp *qp, const struct ib_send_wr *ibwr,
> > >                length += ibwr->sg_list[i].length;
> > >              if (length > (1UL << 31)) {
> > > -            rxe_err_qp(qp, "message length too long");
> > > +            rxe_dbg_qp(qp, "message length too long");
> > >                break;
> > >            }
> > >              if (mask & WR_ATOMIC_MASK) {
> > >                if (length != 8) {
> > > -                rxe_err_qp(qp, "atomic length != 8");
> > > +                rxe_dbg_qp(qp, "atomic length != 8");
> > >                    break;
> > >                }
> > >                if (atomic_wr(ibwr)->remote_addr & 0x7) {
> > > -                rxe_err_qp(qp, "misaligned atomic address");
> > > +                rxe_dbg_qp(qp, "misaligned atomic address");
> > >                    break;
> > >                }
> > >            }
> > >            if (ibwr->send_flags & IB_SEND_INLINE) {
> > >                if (!(mask & WR_INLINE_MASK)) {
> > > -                rxe_err_qp(qp, "opcode doesn't support inline data");
> > > +                rxe_dbg_qp(qp, "opcode doesn't support inline data");
> > >                    break;
> > >                }
> > >                if (length > sq->max_inline) {
> > > -                rxe_err_qp(qp, "inline length too big");
> > > +                rxe_dbg_qp(qp, "inline length too big");
> > >                    break;
> > >                }
> > >            }
> > > @@ -747,7 +727,7 @@ static int init_send_wr(struct rxe_qp *qp, struct rxe_send_wr *wr,
> > >            case IB_WR_SEND:
> > >                break;
> > >            default:
> > > -            rxe_err_qp(qp, "bad wr opcode %d for UD/GSI QP",
> > > +            rxe_dbg_qp(qp, "bad wr opcode %d for UD/GSI QP",
> > >                        wr->opcode);
> > >                return -EINVAL;
> > >            }
> > > @@ -795,7 +775,7 @@ static int init_send_wr(struct rxe_qp *qp, struct rxe_send_wr *wr,
> > >            case IB_WR_ATOMIC_WRITE:
> > >                break;
> > >            default:
> > > -            rxe_err_qp(qp, "unsupported wr opcode %d",
> > > +            rxe_dbg_qp(qp, "unsupported wr opcode %d",
> > >                        wr->opcode);
> > >                return -EINVAL;
> > >                break;
> > > @@ -871,7 +851,7 @@ static int post_one_send(struct rxe_qp *qp, const struct ib_send_wr *ibwr)
> > >          full = queue_full(sq->queue, QUEUE_TYPE_FROM_ULP);
> > >        if (unlikely(full)) {
> > > -        rxe_err_qp(qp, "send queue full");
> > > +        rxe_dbg_qp(qp, "send queue full");
> > >            return -ENOMEM;
> > >        }
> > >    @@ -923,14 +903,14 @@ static int rxe_post_send(struct ib_qp *ibqp, const struct ib_send_wr *wr,
> > >        /* caller has already called destroy_qp */
> > >        if (WARN_ON_ONCE(!qp->valid)) {
> > >            spin_unlock_irqrestore(&qp->state_lock, flags);
> > > -        rxe_err_qp(qp, "qp has been destroyed");
> > > +        rxe_dbg_qp(qp, "qp has been destroyed");
> > >            return -EINVAL;
> > >        }
> > >          if (unlikely(qp_state(qp) < IB_QPS_RTS)) {
> > >            spin_unlock_irqrestore(&qp->state_lock, flags);
> > >            *bad_wr = wr;
> > > -        rxe_err_qp(qp, "qp not ready to send");
> > > +        rxe_dbg_qp(qp, "qp not ready to send");
> > >            return -EINVAL;
> > >        }
> > >        spin_unlock_irqrestore(&qp->state_lock, flags);
> > > @@ -997,7 +977,7 @@ static int post_one_recv(struct rxe_rq *rq, const struct ib_recv_wr *ibwr)
> > >        return 0;
> > >      err_out:
> > > -    rxe_dbg("returned err = %d", err);
> > > +    rxe_err("returned err = %d", err);
> > >        return err;
> > >    }
> > >    @@ -1013,7 +993,7 @@ static int rxe_post_recv(struct ib_qp *ibqp, const struct ib_recv_wr *wr,
> > >        /* caller has already called destroy_qp */
> > >        if (WARN_ON_ONCE(!qp->valid)) {
> > >            spin_unlock_irqrestore(&qp->state_lock, flags);
> > > -        rxe_err_qp(qp, "qp has been destroyed");
> > > +        rxe_dbg_qp(qp, "qp has been destroyed");
> > >            return -EINVAL;
> > >        }
> > >    @@ -1061,7 +1041,7 @@ static int rxe_create_cq(struct ib_cq *ibcq, const struct ib_cq_init_attr *attr,
> > >        struct rxe_dev *rxe = to_rdev(dev);
> > >        struct rxe_cq *cq = to_rcq(ibcq);
> > >        struct rxe_create_cq_resp __user *uresp = NULL;
> > > -    int err, cleanup_err;
> > > +    int err;
> > >          if (udata) {
> > >            if (udata->outlen < sizeof(*uresp)) {
> > > @@ -1100,9 +1080,7 @@ static int rxe_create_cq(struct ib_cq *ibcq, const struct ib_cq_init_attr *attr,
> > >        return 0;
> > >      err_cleanup:
> > > -    cleanup_err = rxe_cleanup(cq);
> > > -    if (cleanup_err)
> > > -        rxe_err_cq(cq, "cleanup failed, err = %d", cleanup_err);
> > > +    rxe_cleanup(cq);
> > >    err_out:
> > >        rxe_err_dev(rxe, "returned err = %d", err);
> > >        return err;
> > > @@ -1207,9 +1185,7 @@ static int rxe_destroy_cq(struct ib_cq *ibcq, struct ib_udata *udata)
> > >            goto err_out;
> > >        }
> > >    -    err = rxe_cleanup(cq);
> > > -    if (err)
> > > -        rxe_err_cq(cq, "cleanup failed, err = %d", err);
> > > +    rxe_cleanup(cq);
> > >          return 0;
> > >    @@ -1257,10 +1233,10 @@ static struct ib_mr *rxe_reg_user_mr(struct ib_pd *ibpd, u64 start,
> > >        struct rxe_dev *rxe = to_rdev(ibpd->device);
> > >        struct rxe_pd *pd = to_rpd(ibpd);
> > >        struct rxe_mr *mr;
> > > -    int err, cleanup_err;
> > > +    int err;
> > >          if (access & ~RXE_ACCESS_SUPPORTED_MR) {
> > > -        rxe_err_pd(pd, "access = %#x not supported (%#x)", access,
> > > +        rxe_dbg_pd(pd, "access = %#x not supported (%#x)", access,
> > >                    RXE_ACCESS_SUPPORTED_MR);
> > >            return ERR_PTR(-EOPNOTSUPP);
> > >        }
> > > @@ -1289,9 +1265,7 @@ static struct ib_mr *rxe_reg_user_mr(struct ib_pd *ibpd, u64 start,
> > >        return &mr->ibmr;
> > >      err_cleanup:
> > > -    cleanup_err = rxe_cleanup(mr);
> > > -    if (cleanup_err)
> > > -        rxe_err_mr(mr, "cleanup failed, err = %d", cleanup_err);
> > > +    rxe_cleanup(mr);
> > >    err_free:
> > >        kfree(mr);
> > >        rxe_err_pd(pd, "returned err = %d", err);
> > > @@ -1311,7 +1285,7 @@ static struct ib_mr *rxe_rereg_user_mr(struct ib_mr *ibmr, int flags,
> > >         * rereg_pd and rereg_access
> > >         */
> > >        if (flags & ~RXE_MR_REREG_SUPPORTED) {
> > > -        rxe_err_mr(mr, "flags = %#x not supported", flags);
> > > +        rxe_dbg_mr(mr, "flags = %#x not supported", flags);
> > >            return ERR_PTR(-EOPNOTSUPP);
> > >        }
> > >    @@ -1323,7 +1297,7 @@ static struct ib_mr *rxe_rereg_user_mr(struct ib_mr *ibmr, int flags,
> > >          if (flags & IB_MR_REREG_ACCESS) {
> > >            if (access & ~RXE_ACCESS_SUPPORTED_MR) {
> > > -            rxe_err_mr(mr, "access = %#x not supported", access);
> > > +            rxe_dbg_mr(mr, "access = %#x not supported", access);
> > >                return ERR_PTR(-EOPNOTSUPP);
> > >            }
> > >            mr->access = access;
> > > @@ -1338,7 +1312,7 @@ static struct ib_mr *rxe_alloc_mr(struct ib_pd *ibpd, enum ib_mr_type mr_type,
> > >        struct rxe_dev *rxe = to_rdev(ibpd->device);
> > >        struct rxe_pd *pd = to_rpd(ibpd);
> > >        struct rxe_mr *mr;
> > > -    int err, cleanup_err;
> > > +    int err;
> > >          if (mr_type != IB_MR_TYPE_MEM_REG) {
> > >            err = -EINVAL;
> > > @@ -1369,9 +1343,7 @@ static struct ib_mr *rxe_alloc_mr(struct ib_pd *ibpd, enum ib_mr_type mr_type,
> > >        return &mr->ibmr;
> > >      err_cleanup:
> > > -    cleanup_err = rxe_cleanup(mr);
> > > -    if (cleanup_err)
> > > -        rxe_err_mr(mr, "cleanup failed, err = %d", err);
> > > +    rxe_cleanup(mr);
> > >    err_free:
> > >        kfree(mr);
> > >    err_out:
> > > @@ -1382,7 +1354,7 @@ static struct ib_mr *rxe_alloc_mr(struct ib_pd *ibpd, enum ib_mr_type mr_type,
> > >    static int rxe_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata)
> > >    {
> > >        struct rxe_mr *mr = to_rmr(ibmr);
> > > -    int err, cleanup_err;
> > > +    int err;
> > >          /* See IBA 10.6.7.2.6 */
> > >        if (atomic_read(&mr->num_mw) > 0) {
> > > @@ -1391,9 +1363,7 @@ static int rxe_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata)
> > >            goto err_out;
> > >        }
> > >    -    cleanup_err = rxe_cleanup(mr);
> > > -    if (cleanup_err)
> > > -        rxe_err_mr(mr, "cleanup failed, err = %d", cleanup_err);
> > > +    rxe_cleanup(mr);
> > >          kfree_rcu(mr);
> > >        return 0;
> > > @@ -1524,7 +1494,7 @@ int rxe_register_device(struct rxe_dev *rxe, const char *ibdev_name)
> > >          err = ib_register_device(dev, ibdev_name, NULL);
> > >        if (err)
> > > -        rxe_dbg_dev(rxe, "failed with error %d\n", err);
> > > +        rxe_err_dev(rxe, "failed with error %d\n", err);
> > >          /*
> > >         * Note that rxe may be invalid at this point if another thread
> > >
> > > base-commit: 5f004bcaee4cb552cf1b46a505f18f08777db7e5