From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
Vasily Averin <vvs@virtuozzo.com>,
"Steven Rostedt (VMware)" <rostedt@goodmis.org>
Subject: [PATCH 5.4 38/39] tracing: Remove WARN_ON in start_thread()
Date: Sun, 6 Dec 2020 12:17:42 +0100 [thread overview]
Message-ID: <20201206111556.483147152@linuxfoundation.org> (raw)
In-Reply-To: <20201206111554.677764505@linuxfoundation.org>
From: Vasily Averin <vvs@virtuozzo.com>
commit 310e3a4b5a4fc718a72201c1e4cf5c64ac6f5442 upstream.
This patch reverts commit 978defee11a5 ("tracing: Do a WARN_ON()
if start_thread() in hwlat is called when thread exists")
.start hook can be legally called several times if according
tracer is stopped
screen window 1
[root@localhost ~]# echo 1 > /sys/kernel/tracing/events/kmem/kfree/enable
[root@localhost ~]# echo 1 > /sys/kernel/tracing/options/pause-on-trace
[root@localhost ~]# less -F /sys/kernel/tracing/trace
screen window 2
[root@localhost ~]# cat /sys/kernel/debug/tracing/tracing_on
0
[root@localhost ~]# echo hwlat > /sys/kernel/debug/tracing/current_tracer
[root@localhost ~]# echo 1 > /sys/kernel/debug/tracing/tracing_on
[root@localhost ~]# cat /sys/kernel/debug/tracing/tracing_on
0
[root@localhost ~]# echo 2 > /sys/kernel/debug/tracing/tracing_on
triggers warning in dmesg:
WARNING: CPU: 3 PID: 1403 at kernel/trace/trace_hwlat.c:371 hwlat_tracer_start+0xc9/0xd0
Link: https://lkml.kernel.org/r/bd4d3e70-400d-9c82-7b73-a2d695e86b58@virtuozzo.com
Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 978defee11a5 ("tracing: Do a WARN_ON() if start_thread() in hwlat is called when thread exists")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/trace/trace_hwlat.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/trace/trace_hwlat.c
+++ b/kernel/trace/trace_hwlat.c
@@ -355,7 +355,7 @@ static int start_kthread(struct trace_ar
struct task_struct *kthread;
int next_cpu;
- if (WARN_ON(hwlat_kthread))
+ if (hwlat_kthread)
return 0;
/* Just pick the first CPU on first iteration */
next prev parent reply other threads:[~2020-12-06 11:44 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-06 11:17 [PATCH 5.4 00/39] 5.4.82-rc1 review Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 01/39] devlink: Hold rtnl lock while reading netdev attributes Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 02/39] ipv6: addrlabel: fix possible memory leak in ip6addrlbl_net_init Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 03/39] net/af_iucv: set correct sk_protocol for child sockets Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 04/39] net/tls: missing received data after fast remote close Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 05/39] net/tls: Protect from calling tls_dev_del for TLS RX twice Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 06/39] rose: Fix Null pointer dereference in rose_send_frame() Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 07/39] sock: set sk_err to ee_errno on dequeue from errq Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 08/39] tcp: Set INET_ECN_xmit configuration in tcp_reinit_congestion_control Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 09/39] tun: honor IOCB_NOWAIT flag Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 10/39] usbnet: ipheth: fix connectivity with iOS 14 Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 11/39] bonding: wait for sysfs kobject destruction before freeing struct slave Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 12/39] staging/octeon: fix up merge error Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 13/39] ima: extend boot_aggregate with kernel measurements Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 14/39] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 15/39] netfilter: bridge: reset skb->pkt_type after NF_INET_POST_ROUTING traversal Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 16/39] ipv4: Fix tos mask in inet_rtm_getroute() Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 17/39] dt-bindings: net: correct interrupt flags in examples Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 18/39] chelsio/chtls: fix panic during unload reload chtls Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 19/39] ibmvnic: Ensure that SCRQ entry reads are correctly ordered Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 20/39] ibmvnic: Fix TX completion error handling Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 21/39] inet_ecn: Fix endianness of checksum update when setting ECT(1) Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 22/39] geneve: pull IP header before ECN decapsulation Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 23/39] net: ip6_gre: set dev->hard_header_len when using header_ops Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 24/39] net/x25: prevent a couple of overflows Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 25/39] cxgb3: fix error return code in t3_sge_alloc_qset() Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 26/39] net: pasemi: fix error return code in pasemi_mac_open() Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 27/39] vxlan: fix error return code in __vxlan_dev_create() Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 28/39] chelsio/chtls: fix a double free in chtls_setkey() Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 29/39] net: mvpp2: Fix error return code in mvpp2_open() Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 30/39] net: skbuff: ensure LSE is pullable before decrementing the MPLS ttl Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 31/39] net: openvswitch: ensure LSE is pullable before reading it Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 32/39] net/sched: act_mpls: " Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 33/39] net/mlx5: DR, Proper handling of unsupported Connect-X6DX SW steering Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 34/39] net/mlx5: Fix wrong address reclaim when command interface is down Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 35/39] ALSA: usb-audio: US16x08: fix value count for level meters Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 36/39] Input: xpad - support Ardwiino Controllers Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 5.4 37/39] Input: i8042 - add ByteSpeed touchpad to noloop table Greg Kroah-Hartman
2020-12-06 11:17 ` Greg Kroah-Hartman [this message]
2020-12-06 11:17 ` [PATCH 5.4 39/39] RDMA/i40iw: Address an mmap handler exploit in i40iw Greg Kroah-Hartman
2020-12-07 8:03 ` [PATCH 5.4 00/39] 5.4.82-rc1 review Naresh Kamboju
2020-12-07 15:55 ` Guenter Roeck
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