Thank you for the patch, Austin.
On Fri, Feb 25, 2022 at 4:52 PM <crash-utility-request@xxxxxxxxxx> wrote:
Date: Fri, 25 Feb 2022 07:19:32 +0000
From: Austin Kim <austindh.kim@xxxxxxxxx>
To: k-hagio-ab@xxxxxxx, crash-utility@xxxxxxxxxx
Cc: kernel-team@xxxxxxx, mikeseohyungjin@xxxxxxxxx
Subject: [PATCH 1/2] ps: Add support to "ps -l" to
properly display process list
Message-ID: <20220225071932.GA1097@raspberrypi>
Content-Type: text/plain; charset=us-ascii
Sometimes kernel image is generated without CONFIG_SCHED_STAT or CONFIG_SCHED_INFO.
Running crash-utility with above kernel image,
"ps -l" options cannot display all processes sorted with most recently-run process
crash> ps -l
ps: last-run timestamps do not exist in this kernel
Usage:
ps [-k|-u|-G] [-s] [-p|-c|-t|-[l|m][-C cpu]|-a|-g|-r|-S]
[pid | task | command] ...
Enter "help ps" for details.
This is because output of 'ps -l' depends on task_struct.sched_info.last_arrival.
Without CONFIG_SCHED_STAT or CONFIG_SCHED_INFO, 'sched_info' field is not included
in task_struct.
So we make 'ps -e' option to access 'exec_start' field of sched_entity.
where 'exec_start' is task_struct.se.exec_start.
With this patch, "ps -l" option works well without CONFIG_SCHED_STAT or
CONFIG_SCHED_INFO.
The history of CONFIG_SCHED_INFO and CONFIG_SCHED_STAT is as below;
- CONFIG_SCHED_INFO: KERNEL_VERSION >= LINUX(4,2,0)
- CONFIG_SCHED_STAT: KERNEL_VERSION < LINUX(4,2,0)
Could you please add the kernel commit ID for the relevant changes?
In addition, I would suggest to fold these two patches as one patch and change the subject as:
"ps: Add support to "ps -l|-m" to properly display process list", what do you think?
Signed-off-by: Austin Kim <austindh.kim@xxxxxxxxx>
---
defs.h | 2 ++
symbols.c | 2 ++
task.c | 17 ++++++++++++++---
3 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/defs.h b/defs.h
index 7d386d2..ed2f5ca 100644
--- a/defs.h
+++ b/defs.h
@@ -1768,6 +1768,8 @@ struct offset_table { /* stash of commonly-used offsets */
long vcpu_struct_rq;
long task_struct_sched_info;
long sched_info_last_arrival;
+ long task_struct_sched_entity;
+ long se_exec_start;
This can be only appended to the end of the offset_table.
For more details, refer to the section "writing patches" in wiki:
Thanks.
Lianbo
long page_objects;
long kmem_cache_oo;
long char_device_struct_cdev;
diff --git a/symbols.c b/symbols.c
index 97fb778..5e2032a 100644
--- a/symbols.c
+++ b/symbols.c
@@ -8892,6 +8892,8 @@ dump_offset_table(char *spec, ulong makestruct)
OFFSET(sched_rt_entity_run_list));
fprintf(fp, " sched_info_last_arrival: %ld\n",
OFFSET(sched_info_last_arrival));
+ fprintf(fp, " se_exec_start: %ld\n",
+ OFFSET(se_exec_start));
fprintf(fp, " task_struct_thread_info: %ld\n",
OFFSET(task_struct_thread_info));
fprintf(fp, " task_struct_stack: %ld\n",
diff --git a/task.c b/task.c
index 864c838..e6fde74 100644
--- a/task.c
+++ b/task.c
@@ -334,9 +334,15 @@ task_init(void)
if (VALID_MEMBER(task_struct_sched_info))
MEMBER_OFFSET_INIT(sched_info_last_arrival,
"sched_info", "last_arrival");
+ MEMBER_OFFSET_INIT(task_struct_sched_entity, "task_struct", "se");
+ if (VALID_MEMBER(task_struct_sched_entity)) {
+ STRUCT_SIZE_INIT(sched_entity, "sched_entity");
+ MEMBER_OFFSET_INIT(se_exec_start, "sched_entity", "exec_start");
+ }
if (VALID_MEMBER(task_struct_last_run) ||
VALID_MEMBER(task_struct_timestamp) ||
- VALID_MEMBER(sched_info_last_arrival)) {
+ VALID_MEMBER(sched_info_last_arrival) ||
+ VALID_MEMBER(se_exec_start)) {
char buf[BUFSIZE];
strcpy(buf, "alias last ps -l");
alias_init(buf);
@@ -3574,7 +3580,8 @@ cmd_ps(void)
case 'l':
if (INVALID_MEMBER(task_struct_last_run) &&
INVALID_MEMBER(task_struct_timestamp) &&
- INVALID_MEMBER(sched_info_last_arrival)) {
+ INVALID_MEMBER(sched_info_last_arrival) &&
+ INVALID_MEMBER(se_exec_start)) {
error(INFO,
"last-run timestamps do not exist in this kernel\n");
argerrs++;
@@ -6020,7 +6027,11 @@ task_last_run(ulong task)
timestamp = tt->last_task_read ? ULONGLONG(tt->task_struct +
OFFSET(task_struct_sched_info) +
OFFSET(sched_info_last_arrival)) : 0;
-
+ else if (VALID_MEMBER(se_exec_start))
+ timestamp = tt->last_task_read ? ULONGLONG(tt->task_struct +
+ OFFSET(task_struct_sched_entity) +
+ OFFSET(se_exec_start)) : 0;
+
return timestamp;
}
--
2.20.1
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