diff options
| author | Guoqing Jiang <guoqing.jiang@linux.dev> | 2021-11-28 21:35:01 +0800 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@nvidia.com> | 2021-11-29 10:56:18 -0400 |
| commit | db6169b5bac1c75ed37cfdaedc7dfb1618f3f362 (patch) | |
| tree | d55434de90abe88244a6b31d45aac22135aa6485 /drivers/infiniband/ulp | |
| parent | b0969f83890bf8b47f5c8bd42539599b2b52fdeb (diff) | |
| download | linux-next-db6169b5bac1c75ed37cfdaedc7dfb1618f3f362.tar.gz | |
RDMA/rtrs: Call {get,put}_cpu_ptr to silence a debug kernel warning
With preemption enabled (CONFIG_DEBUG_PREEMPT=y), the following appeared
when rnbd client tries to map remote block device.
BUG: using smp_processor_id() in preemptible [00000000] code: bash/1733
caller is debug_smp_processor_id+0x17/0x20
CPU: 0 PID: 1733 Comm: bash Not tainted 5.16.0-rc1 #5
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.14.0-0-g155821a-rebuilt.opensuse.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x5d/0x78
dump_stack+0x10/0x12
check_preemption_disabled+0xe4/0xf0
debug_smp_processor_id+0x17/0x20
rtrs_clt_update_all_stats+0x3b/0x70 [rtrs_client]
rtrs_clt_read_req+0xc3/0x380 [rtrs_client]
? rtrs_clt_init_req+0xe3/0x120 [rtrs_client]
rtrs_clt_request+0x1a7/0x320 [rtrs_client]
? 0xffffffffc0ab1000
send_usr_msg+0xbf/0x160 [rnbd_client]
? rnbd_clt_put_sess+0x60/0x60 [rnbd_client]
? send_usr_msg+0x160/0x160 [rnbd_client]
? sg_alloc_table+0x27/0xb0
? sg_zero_buffer+0xd0/0xd0
send_msg_sess_info+0xe9/0x180 [rnbd_client]
? rnbd_clt_put_sess+0x60/0x60 [rnbd_client]
? blk_mq_alloc_tag_set+0x2ef/0x370
rnbd_clt_map_device+0xba8/0xcd0 [rnbd_client]
? send_msg_open+0x200/0x200 [rnbd_client]
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.
While at it, let's make the similar change in rtrs_clt_update_wc_stats.
And for rtrs_clt_inc_failover_cnt, though it was only called inside rcu
section, but it still can be preempted in case CONFIG_PREEMPT_RCU is
enabled, so change it to {get,put}_cpu_ptr pair either.
Link: https://lore.kernel.org/r/20211128133501.38710-1-guoqing.jiang@linux.dev
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'drivers/infiniband/ulp')
| -rw-r--r-- | drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c b/drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c index f7e459fe68be..76e4352fe3f6 100644 --- a/drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c @@ -19,7 +19,7 @@ void rtrs_clt_update_wc_stats(struct rtrs_clt_con *con) int cpu; cpu = raw_smp_processor_id(); - s = this_cpu_ptr(stats->pcpu_stats); + s = get_cpu_ptr(stats->pcpu_stats); if (con->cpu != cpu) { s->cpu_migr.to++; @@ -27,14 +27,16 @@ void rtrs_clt_update_wc_stats(struct rtrs_clt_con *con) s = per_cpu_ptr(stats->pcpu_stats, con->cpu); atomic_inc(&s->cpu_migr.from); } + put_cpu_ptr(stats->pcpu_stats); } void rtrs_clt_inc_failover_cnt(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.failover_cnt++; + put_cpu_ptr(stats->pcpu_stats); } int rtrs_clt_stats_migration_from_cnt_to_str(struct rtrs_clt_stats *stats, char *buf) @@ -169,9 +171,10 @@ 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) |