From 88b72b31e15f9dfed069ede5416bb71040e0d299 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 18 May 2018 08:47:13 -0700 Subject: proc: Consolidate task->comm formatting into proc_task_name() proc shows task->comm in three places - comm, stat, status - and each is fetching and formatting task->comm slighly differently. This patch renames task_name() to proc_task_name(), makes it more generic, and updates all three paths to use it. This will enable expanding comm reporting for workqueue workers. Signed-off-by: Tejun Heo --- fs/proc/array.c | 26 +++++++++++++++----------- fs/proc/base.c | 5 ++--- fs/proc/internal.h | 2 ++ 3 files changed, 19 insertions(+), 14 deletions(-) (limited to 'fs/proc') diff --git a/fs/proc/array.c b/fs/proc/array.c index ae2c807fd719..f29221e95792 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -95,7 +95,7 @@ #include #include "internal.h" -static inline void task_name(struct seq_file *m, struct task_struct *p) +void proc_task_name(struct seq_file *m, struct task_struct *p, bool escape) { char *buf; size_t size; @@ -104,13 +104,17 @@ static inline void task_name(struct seq_file *m, struct task_struct *p) get_task_comm(tcomm, p); - seq_puts(m, "Name:\t"); - size = seq_get_buf(m, &buf); - ret = string_escape_str(tcomm, buf, size, ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\"); - seq_commit(m, ret < size ? ret : -1); + if (escape) { + ret = string_escape_str(tcomm, buf, size, + ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\"); + if (ret >= size) + ret = -1; + } else { + ret = strscpy(buf, tcomm, size); + } - seq_putc(m, '\n'); + seq_commit(m, ret); } /* @@ -365,7 +369,10 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns, { struct mm_struct *mm = get_task_mm(task); - task_name(m, task); + seq_puts(m, "Name:\t"); + proc_task_name(m, task, true); + seq_putc(m, '\n'); + task_state(m, ns, pid, task); if (mm) { @@ -400,7 +407,6 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns, u64 cutime, cstime, utime, stime; u64 cgtime, gtime; unsigned long rsslim = 0; - char tcomm[sizeof(task->comm)]; unsigned long flags; state = *get_task_state(task); @@ -427,8 +433,6 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns, } } - get_task_comm(tcomm, task); - sigemptyset(&sigign); sigemptyset(&sigcatch); cutime = cstime = utime = stime = 0; @@ -495,7 +499,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns, seq_put_decimal_ull(m, "", pid_nr_ns(pid, ns)); seq_puts(m, " ("); - seq_puts(m, tcomm); + proc_task_name(m, task, false); seq_puts(m, ") "); seq_putc(m, state); seq_put_decimal_ll(m, " ", ppid); diff --git a/fs/proc/base.c b/fs/proc/base.c index 1b2ede6abcdf..bb192a699bce 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1565,9 +1565,8 @@ static int comm_show(struct seq_file *m, void *v) if (!p) return -ESRCH; - task_lock(p); - seq_printf(m, "%s\n", p->comm); - task_unlock(p); + proc_task_name(m, p, false); + seq_putc(m, '\n'); put_task_struct(p); diff --git a/fs/proc/internal.h b/fs/proc/internal.h index 0f1692e63cb6..b823fac621d2 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -131,6 +131,8 @@ unsigned name_to_int(const struct qstr *qstr); */ extern const struct file_operations proc_tid_children_operations; +extern void proc_task_name(struct seq_file *m, struct task_struct *p, + bool escape); extern int proc_tid_stat(struct seq_file *, struct pid_namespace *, struct pid *, struct task_struct *); extern int proc_tgid_stat(struct seq_file *, struct pid_namespace *, -- cgit v1.2.1 From 6b59808bfe482642287ddf3fe9d4cccb10756652 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 18 May 2018 08:47:13 -0700 Subject: workqueue: Show the latest workqueue name in /proc/PID/{comm,stat,status} There can be a lot of workqueue workers and they all show up with the cryptic kworker/* names making it difficult to understand which is doing what and how they came to be. # ps -ef | grep kworker root 4 2 0 Feb25 ? 00:00:00 [kworker/0:0H] root 6 2 0 Feb25 ? 00:00:00 [kworker/u112:0] root 19 2 0 Feb25 ? 00:00:00 [kworker/1:0H] root 25 2 0 Feb25 ? 00:00:00 [kworker/2:0H] root 31 2 0 Feb25 ? 00:00:00 [kworker/3:0H] ... This patch makes workqueue workers report the latest workqueue it was executing for through /proc/PID/{comm,stat,status}. The extra information is appended to the kthread name with intervening '+' if currently executing, otherwise '-'. # cat /proc/25/comm kworker/2:0-events_power_efficient # cat /proc/25/stat 25 (kworker/2:0-events_power_efficient) I 2 0 0 0 -1 69238880 0 0... # grep Name /proc/25/status Name: kworker/2:0-events_power_efficient Unfortunately, ps(1) truncates comm to 15 characters, # ps 25 PID TTY STAT TIME COMMAND 25 ? I 0:00 [kworker/2:0-eve] making it a lot less useful; however, this should be an easy fix from ps(1) side. Signed-off-by: Tejun Heo Suggested-by: Linus Torvalds Cc: Craig Small --- fs/proc/array.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'fs/proc') diff --git a/fs/proc/array.c b/fs/proc/array.c index f29221e95792..bb1d3619ca12 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -99,10 +99,13 @@ void proc_task_name(struct seq_file *m, struct task_struct *p, bool escape) { char *buf; size_t size; - char tcomm[sizeof(p->comm)]; + char tcomm[64]; int ret; - get_task_comm(tcomm, p); + if (p->flags & PF_WQ_WORKER) + wq_worker_comm(tcomm, sizeof(tcomm), p); + else + __get_task_comm(tcomm, sizeof(tcomm), p); size = seq_get_buf(m, &buf); if (escape) { -- cgit v1.2.1