Linux-RDMA Archive mirror
 help / color / mirror / Atom feed
From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Manjunath Patil <manjunath.b.patil@oracle.com>,
	Leon Romanovsky <leon@kernel.org>,
	Sasha Levin <sashal@kernel.org>,
	markzhang@nvidia.com, linux-rdma@vger.kernel.org
Subject: [PATCH AUTOSEL 6.6 65/75] RDMA/cm: add timeout to cm_destroy_id wait
Date: Fri, 29 Mar 2024 08:42:46 -0400	[thread overview]
Message-ID: <20240329124330.3089520-65-sashal@kernel.org> (raw)
In-Reply-To: <20240329124330.3089520-1-sashal@kernel.org>

From: Manjunath Patil <manjunath.b.patil@oracle.com>

[ Upstream commit 96d9cbe2f2ff7abde021bac75eafaceabe9a51fa ]

Add timeout to cm_destroy_id, so that userspace can trigger any data
collection that would help in analyzing the cause of delay in destroying
the cm_id.

New noinline function helps dtrace/ebpf programs to hook on to it.
Existing functionality isn't changed except triggering a probe-able new
function at every timeout interval.

We have seen cases where CM messages stuck with MAD layer (either due to
software bug or faulty HCA), leading to cm_id getting stuck in the
following call stack. This patch helps in resolving such issues faster.

kernel: ... INFO: task XXXX:56778 blocked for more than 120 seconds.
...
	Call Trace:
	__schedule+0x2bc/0x895
	schedule+0x36/0x7c
	schedule_timeout+0x1f6/0x31f
 	? __slab_free+0x19c/0x2ba
	wait_for_completion+0x12b/0x18a
	? wake_up_q+0x80/0x73
	cm_destroy_id+0x345/0x610 [ib_cm]
	ib_destroy_cm_id+0x10/0x20 [ib_cm]
	rdma_destroy_id+0xa8/0x300 [rdma_cm]
	ucma_destroy_id+0x13e/0x190 [rdma_ucm]
	ucma_write+0xe0/0x160 [rdma_ucm]
	__vfs_write+0x3a/0x16d
	vfs_write+0xb2/0x1a1
	? syscall_trace_enter+0x1ce/0x2b8
	SyS_write+0x5c/0xd3
	do_syscall_64+0x79/0x1b9
	entry_SYSCALL_64_after_hwframe+0x16d/0x0

Signed-off-by: Manjunath Patil <manjunath.b.patil@oracle.com>
Link: https://lore.kernel.org/r/20240309063323.458102-1-manjunath.b.patil@oracle.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/infiniband/core/cm.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
index ff58058aeadca..bf0df6ee4f785 100644
--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -34,6 +34,7 @@ MODULE_AUTHOR("Sean Hefty");
 MODULE_DESCRIPTION("InfiniBand CM");
 MODULE_LICENSE("Dual BSD/GPL");
 
+#define CM_DESTROY_ID_WAIT_TIMEOUT 10000 /* msecs */
 static const char * const ibcm_rej_reason_strs[] = {
 	[IB_CM_REJ_NO_QP]			= "no QP",
 	[IB_CM_REJ_NO_EEC]			= "no EEC",
@@ -1025,10 +1026,20 @@ static void cm_reset_to_idle(struct cm_id_private *cm_id_priv)
 	}
 }
 
+static noinline void cm_destroy_id_wait_timeout(struct ib_cm_id *cm_id)
+{
+	struct cm_id_private *cm_id_priv;
+
+	cm_id_priv = container_of(cm_id, struct cm_id_private, id);
+	pr_err("%s: cm_id=%p timed out. state=%d refcnt=%d\n", __func__,
+	       cm_id, cm_id->state, refcount_read(&cm_id_priv->refcount));
+}
+
 static void cm_destroy_id(struct ib_cm_id *cm_id, int err)
 {
 	struct cm_id_private *cm_id_priv;
 	struct cm_work *work;
+	int ret;
 
 	cm_id_priv = container_of(cm_id, struct cm_id_private, id);
 	spin_lock_irq(&cm_id_priv->lock);
@@ -1135,7 +1146,14 @@ static void cm_destroy_id(struct ib_cm_id *cm_id, int err)
 
 	xa_erase(&cm.local_id_table, cm_local_id(cm_id->local_id));
 	cm_deref_id(cm_id_priv);
-	wait_for_completion(&cm_id_priv->comp);
+	do {
+		ret = wait_for_completion_timeout(&cm_id_priv->comp,
+						  msecs_to_jiffies(
+						  CM_DESTROY_ID_WAIT_TIMEOUT));
+		if (!ret) /* timeout happened */
+			cm_destroy_id_wait_timeout(cm_id);
+	} while (!ret);
+
 	while ((work = cm_dequeue_work(cm_id_priv)) != NULL)
 		cm_free_work(work);
 
-- 
2.43.0


           reply	other threads:[~2024-03-29 12:45 UTC|newest]

Thread overview: expand[flat|nested]  mbox.gz  Atom feed
 [parent not found: <20240329124330.3089520-1-sashal@kernel.org>]

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=20240329124330.3089520-65-sashal@kernel.org \
    --to=sashal@kernel.org \
    --cc=leon@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-rdma@vger.kernel.org \
    --cc=manjunath.b.patil@oracle.com \
    --cc=markzhang@nvidia.com \
    --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;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).