All of lore.kernel.org
 help / color / mirror / Atom feed
From: Guoqing Jiang <guoqing.jiang@linux.dev>
To: haris.iqbal@ionos.com, jinpu.wang@ionos.com, jgg@ziepe.ca
Cc: linux-rdma@vger.kernel.org, Guoqing Jiang <guoqing.jiang@linux.dev>
Subject: [PATCH] RDMA/rtrs: Call {get,put}_cpu_ptr to silence a debug kernel warning
Date: Sun, 21 Nov 2021 22:22:23 +0800	[thread overview]
Message-ID: <20211121142223.22887-1-guoqing.jiang@linux.dev> (raw)

With preemption enabled (CONFIG_DEBUG_PREEMPT=y), the following appeared
when rnbd client tries to map remote block device.

[ 2123.221071] BUG: using smp_processor_id() in preemptible [00000000] code: bash/1733
[ 2123.221175] caller is debug_smp_processor_id+0x17/0x20
[ 2123.221214] CPU: 0 PID: 1733 Comm: bash Not tainted 5.16.0-rc1 #5
[ 2123.221218] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.14.0-0-g155821a-rebuilt.opensuse.org 04/01/2014
[ 2123.221229] Call Trace:
[ 2123.221231]  <TASK>
[ 2123.221235]  dump_stack_lvl+0x5d/0x78
[ 2123.221252]  dump_stack+0x10/0x12
[ 2123.221257]  check_preemption_disabled+0xe4/0xf0
[ 2123.221266]  debug_smp_processor_id+0x17/0x20
[ 2123.221271]  rtrs_clt_update_all_stats+0x3b/0x70 [rtrs_client]
[ 2123.221285]  rtrs_clt_read_req+0xc3/0x380 [rtrs_client]
[ 2123.221298]  ? rtrs_clt_init_req+0xe3/0x120 [rtrs_client]
[ 2123.221321]  rtrs_clt_request+0x1a7/0x320 [rtrs_client]
[ 2123.221340]  ? 0xffffffffc0ab1000
[ 2123.221357]  send_usr_msg+0xbf/0x160 [rnbd_client]
[ 2123.221370]  ? rnbd_clt_put_sess+0x60/0x60 [rnbd_client]
[ 2123.221377]  ? send_usr_msg+0x160/0x160 [rnbd_client]
[ 2123.221386]  ? sg_alloc_table+0x27/0xb0
[ 2123.221395]  ? sg_zero_buffer+0xd0/0xd0
[ 2123.221407]  send_msg_sess_info+0xe9/0x180 [rnbd_client]
[ 2123.221413]  ? rnbd_clt_put_sess+0x60/0x60 [rnbd_client]
[ 2123.221429]  ? blk_mq_alloc_tag_set+0x2ef/0x370
[ 2123.221447]  rnbd_clt_map_device+0xba8/0xcd0 [rnbd_client]
[ 2123.221462]  ? send_msg_open+0x200/0x200 [rnbd_client]
[ 2123.221479]  rnbd_clt_map_device_store+0x3e5/0x620 [rnbd_client

To supress the calltrace, let's call get_cpu_ptr/put_cpu_ptr pair in
rtrs_clt_update_rdma_stats to disable preemption when accessing per-cpu
variable.

Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
---
 drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c b/drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c
index f7e459fe68be..6ff72f2b1a3a 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c
@@ -169,9 +169,10 @@ static inline void rtrs_clt_update_rdma_stats(struct rtrs_clt_stats *stats,
 {
 	struct rtrs_clt_stats_pcpu *s;
 
-	s = this_cpu_ptr(stats->pcpu_stats);
+	s = get_cpu_ptr(stats->pcpu_stats);
 	s->rdma.dir[d].cnt++;
 	s->rdma.dir[d].size_total += size;
+	put_cpu_ptr(stats->pcpu_stats);
 }
 
 void rtrs_clt_update_all_stats(struct rtrs_clt_io_req *req, int dir)
-- 
2.31.1


             reply	other threads:[~2021-11-21 14:22 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-21 14:22 Guoqing Jiang [this message]
2021-11-22  7:25 ` [PATCH] RDMA/rtrs: Call {get,put}_cpu_ptr to silence a debug kernel warning Jinpu Wang
2021-11-22  7:44 ` Leon Romanovsky
2021-11-22  8:20   ` Jinpu Wang
2021-11-22  8:23     ` Guoqing Jiang

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=20211121142223.22887-1-guoqing.jiang@linux.dev \
    --to=guoqing.jiang@linux.dev \
    --cc=haris.iqbal@ionos.com \
    --cc=jgg@ziepe.ca \
    --cc=jinpu.wang@ionos.com \
    --cc=linux-rdma@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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.