From: Yafang Shao <laoar.shao@gmail.com>
To: keescook@chromium.org, rostedt@goodmis.org, peterz@infradead.org,
pmladek@suse.com, viro@zeniv.linux.org.uk,
akpm@linux-foundation.org, valentin.schneider@arm.com,
mathieu.desnoyers@efficios.com, qiang.zhang@windriver.com,
robdclark@chromium.org, christian@brauner.io,
dietmar.eggemann@arm.com, mingo@redhat.com,
juri.lelli@redhat.com, vincent.guittot@linaro.org,
bsegall@google.com, mgorman@suse.de, bristot@redhat.com
Cc: linux-kernel@vger.kernel.org, Yafang Shao <laoar.shao@gmail.com>
Subject: [PATCH v3 3/4] sched.h: extend task comm from 16 to 24 for CONFIG_BASE_FULL
Date: Sun, 10 Oct 2021 10:24:28 +0000 [thread overview]
Message-ID: <20211010102429.99577-4-laoar.shao@gmail.com> (raw)
In-Reply-To: <20211010102429.99577-1-laoar.shao@gmail.com>
When I was implementing a new per-cpu kthread cfs_migration, I found the
comm of it "cfs_migration/%u" is truncated due to the limitation of
TASK_COMM_LEN. For example, the comm of the percpu thread on CPU10~19 are
all with the same name "cfs_migration/1", which will confuse the user. This
issue is not critical, because we can get the corresponding CPU from the
task's Cpus_allowed. But for kthreads correspoinding to other hardware
devices, it is not easy to get the detailed device info from task comm,
for example,
jbd2/nvme0n1p2-
xfs-reclaim/sdf
We can also shorten the name to work around this problem, but I find
there are so many truncated kthreads:
rcu_tasks_kthre
rcu_tasks_rude_
rcu_tasks_trace
poll_mpt3sas0_s
ext4-rsv-conver
xfs-reclaim/sd{a, b, c, ...}
xfs-blockgc/sd{a, b, c, ...}
xfs-inodegc/sd{a, b, c, ...}
audit_send_repl
ecryptfs-kthrea
vfio-irqfd-clea
jbd2/nvme0n1p2-
...
We should improve this problem fundamentally.
This patch extends the size of task comm to 24 bytes, which is the
same length with workqueue's, for the CONFIG_BASE_FULL case. And for the
CONFIG_BASE_SMALL case, the size of task comm is still kept as 16 bytes.
Suggested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Petr Mladek <pmladek@suse.com>
---
include/linux/sched.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 39039ce8ac4c..e0796068dee0 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -275,7 +275,11 @@ struct task_group;
#define get_current_state() READ_ONCE(current->__state)
/* Task command name length: */
+#if CONFIG_BASE_SMALL
#define TASK_COMM_LEN 16
+#else
+#define TASK_COMM_LEN 24
+#endif
extern void scheduler_tick(void);
--
2.18.2
next prev parent reply other threads:[~2021-10-10 10:25 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-10 10:24 [PATCH v3 0/4] task_struct: extend task comm from 16 to 24 for CONFIG_BASE_FULL Yafang Shao
2021-10-10 10:24 ` [PATCH v3 1/4] connector: use __get_task_comm in proc_comm_connector Yafang Shao
2021-10-10 10:24 ` [PATCH v3 2/4] fs/exec: use strscpy instead of strlcpy in __set_task_comm Yafang Shao
2021-10-10 10:24 ` Yafang Shao [this message]
2021-10-10 12:52 ` [PATCH v3 3/4] sched.h: extend task comm from 16 to 24 for CONFIG_BASE_FULL kernel test robot
2021-10-10 13:05 ` Yafang Shao
2021-10-14 7:27 ` [sched.h] 317419b91e: perf-sanity-tests.Parse_sched_tracepoints_fields.fail kernel test robot
2021-10-14 7:27 ` kernel test robot
2021-10-14 9:24 ` Yafang Shao
2021-10-14 9:24 ` Yafang Shao
2021-10-14 12:42 ` Mathieu Desnoyers
2021-10-14 12:42 ` Mathieu Desnoyers
2021-10-14 13:05 ` Yafang Shao
2021-10-14 13:05 ` Yafang Shao
2021-10-14 13:09 ` Mathieu Desnoyers
2021-10-14 13:09 ` Mathieu Desnoyers
2021-10-14 13:11 ` Yafang Shao
2021-10-14 13:11 ` Yafang Shao
2021-10-14 13:50 ` Mathieu Desnoyers
2021-10-14 13:50 ` Mathieu Desnoyers
2021-10-14 14:40 ` Yafang Shao
2021-10-14 14:40 ` Yafang Shao
2021-10-14 14:48 ` Steven Rostedt
2021-10-14 14:48 ` Steven Rostedt
2021-10-14 15:05 ` Yafang Shao
2021-10-14 15:05 ` Yafang Shao
2021-10-14 16:14 ` Kees Cook
2021-10-14 16:14 ` Kees Cook
2021-10-15 2:05 ` Yafang Shao
2021-10-15 2:05 ` Yafang Shao
2021-10-15 2:14 ` Steven Rostedt
2021-10-15 2:14 ` Steven Rostedt
2021-10-15 2:20 ` Yafang Shao
2021-10-15 2:20 ` Yafang Shao
2021-10-19 16:51 ` Arnaldo Carvalho de Melo
2021-10-19 16:51 ` Arnaldo Carvalho de Melo
2021-10-20 4:01 ` Yafang Shao
2021-10-20 4:01 ` Yafang Shao
2021-10-10 10:24 ` [PATCH v3 4/4] kernel/kthread: show a warning if kthread's comm is truncated Yafang Shao
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