From: Mike Marciniszyn <mike.marciniszyn@intel.com>
To: stable@vger.kernel.org
Cc: linux-rdma@vger.kernel.org, stable-commits@vger.kernel.org
Subject: [PATCH] IB/hfi1: Avoid hardlockup with flushlist_lock
Date: Mon, 24 Jun 2019 12:26:23 -0400 [thread overview]
Message-ID: <20190624162623.184356.72785.stgit@awfm-01.aw.intel.com> (raw)
commit cf131a81967583ae737df6383a0893b9fee75b4e upstream.
Heavy contention of the sde flushlist_lock can cause hard lockups at
extreme scale when the flushing logic is under stress.
Mitigate by replacing the item at a time copy to the local list with
an O(1) list_splice_init() and using the high priority work queue to
do the flushes.
Ported to linux-4.19.y.
Fixes: 7724105686e7 ("IB/hfi1: add driver files")
Cc: <stable@vger.kernel.org>
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>
---
drivers/infiniband/hw/hfi1/sdma.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/drivers/infiniband/hw/hfi1/sdma.c b/drivers/infiniband/hw/hfi1/sdma.c
index 88e326d..d648a41 100644
--- a/drivers/infiniband/hw/hfi1/sdma.c
+++ b/drivers/infiniband/hw/hfi1/sdma.c
@@ -410,10 +410,7 @@ static void sdma_flush(struct sdma_engine *sde)
sdma_flush_descq(sde);
spin_lock_irqsave(&sde->flushlist_lock, flags);
/* copy flush list */
- list_for_each_entry_safe(txp, txp_next, &sde->flushlist, list) {
- list_del_init(&txp->list);
- list_add_tail(&txp->list, &flushlist);
- }
+ list_splice_init(&sde->flushlist, &flushlist);
spin_unlock_irqrestore(&sde->flushlist_lock, flags);
/* flush from flush list */
list_for_each_entry_safe(txp, txp_next, &flushlist, list)
@@ -2426,7 +2423,7 @@ int sdma_send_txreq(struct sdma_engine *sde,
wait->tx_count++;
wait->count += tx->num_desc;
}
- schedule_work(&sde->flush_worker);
+ queue_work_on(sde->cpu, system_highpri_wq, &sde->flush_worker);
ret = -ECOMM;
goto unlock;
nodesc:
@@ -2526,7 +2523,7 @@ int sdma_send_txlist(struct sdma_engine *sde, struct iowait *wait,
}
}
spin_unlock(&sde->flushlist_lock);
- schedule_work(&sde->flush_worker);
+ queue_work_on(sde->cpu, system_highpri_wq, &sde->flush_worker);
ret = -ECOMM;
goto update_tail;
nodesc:
next reply other threads:[~2019-06-24 16:26 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-24 16:26 Mike Marciniszyn [this message]
-- strict thread matches above, loose matches on Subject: below --
2019-06-24 16:14 [PATCH] IB/hfi1: Avoid hardlockup with flushlist_lock Mike Marciniszyn
2019-06-24 20:17 ` Sasha Levin
2019-06-24 15:56 Mike Marciniszyn
2019-06-24 20:17 ` Sasha Levin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190624162623.184356.72785.stgit@awfm-01.aw.intel.com \
--to=mike.marciniszyn@intel.com \
--cc=linux-rdma@vger.kernel.org \
--cc=stable-commits@vger.kernel.org \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox