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author | Mike Marciniszyn <mike.marciniszyn@intel.com> | 2017-04-09 20:16:35 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-05-20 15:30:59 +0300 |
commit | d187c9e135d307ffba95c8fc0c550c3faa9be017 (patch) | |
tree | 53f4fa018219b7ea13786045219da0693f431b71 | |
parent | 04692adb3aacb0b64f84a07215367a6d8b0f79cc (diff) | |
download | linux-d187c9e135d307ffba95c8fc0c550c3faa9be017.tar.xz |
IB/hfi1: Prevent kernel QP post send hard lockups
commit b6eac931b9bb2bce4db7032c35b41e5e34ec22a5 upstream.
The driver progress routines can call cond_resched() when
a timeslice is exhausted and irqs are enabled.
If the ULP had been holding a spin lock without disabling irqs and
the post send directly called the progress routine, the cond_resched()
could yield allowing another thread from the same ULP to deadlock
on that same lock.
Correct by replacing the current hfi1_do_send() calldown with a unique
one for post send and adding an argument to hfi1_do_send() to indicate
that the send engine is running in a thread. If the routine is not
running in a thread, avoid calling cond_resched().
Fixes: Commit 831464ce4b74 ("IB/hfi1: Don't call cond_resched in atomic mode when sending packets")
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | drivers/infiniband/hw/hfi1/ruc.c | 26 | ||||
-rw-r--r-- | drivers/infiniband/hw/hfi1/verbs.c | 4 | ||||
-rw-r--r-- | drivers/infiniband/hw/hfi1/verbs.h | 6 |
3 files changed, 22 insertions, 14 deletions
diff --git a/drivers/infiniband/hw/hfi1/ruc.c b/drivers/infiniband/hw/hfi1/ruc.c index 717ed4b159d3..6e46a6c002a7 100644 --- a/drivers/infiniband/hw/hfi1/ruc.c +++ b/drivers/infiniband/hw/hfi1/ruc.c @@ -1,5 +1,5 @@ /* - * Copyright(c) 2015, 2016 Intel Corporation. + * Copyright(c) 2015 - 2017 Intel Corporation. * * This file is provided under a dual BSD/GPLv2 license. When using or * redistributing this file, you may do so under either license. @@ -823,23 +823,29 @@ void hfi1_make_ruc_header(struct rvt_qp *qp, struct ib_other_headers *ohdr, /* when sending, force a reschedule every one of these periods */ #define SEND_RESCHED_TIMEOUT (5 * HZ) /* 5s in jiffies */ +void hfi1_do_send_from_rvt(struct rvt_qp *qp) +{ + hfi1_do_send(qp, false); +} + void _hfi1_do_send(struct work_struct *work) { struct iowait *wait = container_of(work, struct iowait, iowork); struct rvt_qp *qp = iowait_to_qp(wait); - hfi1_do_send(qp); + hfi1_do_send(qp, true); } /** * hfi1_do_send - perform a send on a QP * @work: contains a pointer to the QP + * @in_thread: true if in a workqueue thread * * Process entries in the send work queue until credit or queue is * exhausted. Only allow one CPU to send a packet per QP. * Otherwise, two threads could send packets out of order. */ -void hfi1_do_send(struct rvt_qp *qp) +void hfi1_do_send(struct rvt_qp *qp, bool in_thread) { struct hfi1_pkt_state ps; struct hfi1_qp_priv *priv = qp->priv; @@ -907,8 +913,10 @@ void hfi1_do_send(struct rvt_qp *qp) qp->s_hdrwords = 0; /* allow other tasks to run */ if (unlikely(time_after(jiffies, timeout))) { - if (workqueue_congested(cpu, - ps.ppd->hfi1_wq)) { + if (!in_thread || + workqueue_congested( + cpu, + ps.ppd->hfi1_wq)) { spin_lock_irqsave( &qp->s_lock, ps.flags); @@ -921,11 +929,9 @@ void hfi1_do_send(struct rvt_qp *qp) *ps.ppd->dd->send_schedule); return; } - if (!irqs_disabled()) { - cond_resched(); - this_cpu_inc( - *ps.ppd->dd->send_schedule); - } + cond_resched(); + this_cpu_inc( + *ps.ppd->dd->send_schedule); timeout = jiffies + (timeout_int) / 8; } spin_lock_irqsave(&qp->s_lock, ps.flags); diff --git a/drivers/infiniband/hw/hfi1/verbs.c b/drivers/infiniband/hw/hfi1/verbs.c index 95ed4d6da510..6002aa9317ef 100644 --- a/drivers/infiniband/hw/hfi1/verbs.c +++ b/drivers/infiniband/hw/hfi1/verbs.c @@ -1,5 +1,5 @@ /* - * Copyright(c) 2015, 2016 Intel Corporation. + * Copyright(c) 2015 - 2017 Intel Corporation. * * This file is provided under a dual BSD/GPLv2 license. When using or * redistributing this file, you may do so under either license. @@ -1832,7 +1832,7 @@ int hfi1_register_ib_device(struct hfi1_devdata *dd) dd->verbs_dev.rdi.driver_f.qp_priv_free = qp_priv_free; dd->verbs_dev.rdi.driver_f.free_all_qps = free_all_qps; dd->verbs_dev.rdi.driver_f.notify_qp_reset = notify_qp_reset; - dd->verbs_dev.rdi.driver_f.do_send = hfi1_do_send; + dd->verbs_dev.rdi.driver_f.do_send = hfi1_do_send_from_rvt; dd->verbs_dev.rdi.driver_f.schedule_send = hfi1_schedule_send; dd->verbs_dev.rdi.driver_f.schedule_send_no_lock = _hfi1_schedule_send; dd->verbs_dev.rdi.driver_f.get_pmtu_from_attr = get_pmtu_from_attr; diff --git a/drivers/infiniband/hw/hfi1/verbs.h b/drivers/infiniband/hw/hfi1/verbs.h index e6b893010e6d..228dc5545159 100644 --- a/drivers/infiniband/hw/hfi1/verbs.h +++ b/drivers/infiniband/hw/hfi1/verbs.h @@ -1,5 +1,5 @@ /* - * Copyright(c) 2015, 2016 Intel Corporation. + * Copyright(c) 2015 - 2017 Intel Corporation. * * This file is provided under a dual BSD/GPLv2 license. When using or * redistributing this file, you may do so under either license. @@ -370,7 +370,9 @@ void hfi1_make_ruc_header(struct rvt_qp *qp, struct ib_other_headers *ohdr, void _hfi1_do_send(struct work_struct *work); -void hfi1_do_send(struct rvt_qp *qp); +void hfi1_do_send_from_rvt(struct rvt_qp *qp); + +void hfi1_do_send(struct rvt_qp *qp, bool in_thread); void hfi1_send_complete(struct rvt_qp *qp, struct rvt_swqe *wqe, enum ib_wc_status status); |