* Re: [PATCH sched_ext/for-6.12] sched_ext: Improve logging around enable/disable
2024-08-08 0:52 [PATCH sched_ext/for-6.12] sched_ext: Improve logging around enable/disable Tejun Heo
@ 2024-08-08 12:38 ` Phil Auld
2024-08-08 17:00 ` David Vernet
2024-08-08 23:47 ` [PATCH v2 " Tejun Heo
2 siblings, 0 replies; 4+ messages in thread
From: Phil Auld @ 2024-08-08 12:38 UTC (permalink / raw)
To: Tejun Heo; +Cc: David Vernet, linux-kernel, kernel-team
On Wed, Aug 07, 2024 at 02:52:50PM -1000 Tejun Heo wrote:
> sched_ext currently doesn't generate messages when the BPF scheduler is
> enabled and disabled unless there are errors. It is useful to have paper
> trail. Improve logging around enable/disable:
>
> - Generate info messages on enable and non-error disable.
>
> - Update error exit message formatting so that it's consistent with
> non-error message. Also, prefix ei->msg with the BPF scheduler's name to
> make it clear where the message is coming from.
>
> - Shorten scx_exit_reason() strings for SCX_EXIT_UNREG* for brevity and
> consistency.
>
Thanks! That looks very helpful.
Reviewed-by: Phil Auld <pauld@redhat.com>
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Suggested-by: Phil Auld <pauld@redhat.com>
> ---
> kernel/sched/ext.c | 21 +++++++++++++--------
> 1 file changed, 13 insertions(+), 8 deletions(-)
>
> diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
> index 60a7eb7d8a9e..eea2fda8e099 100644
> --- a/kernel/sched/ext.c
> +++ b/kernel/sched/ext.c
> @@ -4004,11 +4004,11 @@ static const char *scx_exit_reason(enum scx_exit_kind kind)
> {
> switch (kind) {
> case SCX_EXIT_UNREG:
> - return "Scheduler unregistered from user space";
> + return "unregistered from user space";
> case SCX_EXIT_UNREG_BPF:
> - return "Scheduler unregistered from BPF";
> + return "unregistered from BPF";
> case SCX_EXIT_UNREG_KERN:
> - return "Scheduler unregistered from the main kernel";
> + return "unregistered from the main kernel";
> case SCX_EXIT_SYSRQ:
> return "disabled by sysrq-S";
> case SCX_EXIT_ERROR:
> @@ -4126,14 +4126,17 @@ static void scx_ops_disable_workfn(struct kthread_work *work)
> percpu_up_write(&scx_fork_rwsem);
>
> if (ei->kind >= SCX_EXIT_ERROR) {
> - printk(KERN_ERR "sched_ext: BPF scheduler \"%s\" errored, disabling\n", scx_ops.name);
> + pr_err("sched_ext: BPF scheduler \"%s\" disabled (%s)\n",
> + scx_ops.name, ei->reason);
>
> - if (ei->msg[0] == '\0')
> - printk(KERN_ERR "sched_ext: %s\n", ei->reason);
> - else
> - printk(KERN_ERR "sched_ext: %s (%s)\n", ei->reason, ei->msg);
> + if (ei->msg[0] != '\0')
> + printk(KERN_ERR "sched_ext: %s: %s\n",
> + scx_ops.name, ei->msg);
>
> stack_trace_print(ei->bt, ei->bt_len, 2);
> + } else {
> + pr_info("sched_ext: BPF scheduler \"%s\" disabled (%s)\n",
> + scx_ops.name, ei->reason);
> }
>
> if (scx_ops.exit)
> @@ -4808,6 +4811,8 @@ static int scx_ops_enable(struct sched_ext_ops *ops, struct bpf_link *link)
> if (!(ops->flags & SCX_OPS_SWITCH_PARTIAL))
> static_branch_enable(&__scx_switched_all);
>
> + pr_info("sched_ext: BPF scheduler \"%s\" enabled%s\n",
> + scx_ops.name, scx_switched_all() ? "" : " (partial)");
> kobject_uevent(scx_root_kobj, KOBJ_ADD);
> mutex_unlock(&scx_ops_enable_mutex);
>
>
--
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH sched_ext/for-6.12] sched_ext: Improve logging around enable/disable
2024-08-08 0:52 [PATCH sched_ext/for-6.12] sched_ext: Improve logging around enable/disable Tejun Heo
2024-08-08 12:38 ` Phil Auld
@ 2024-08-08 17:00 ` David Vernet
2024-08-08 23:47 ` [PATCH v2 " Tejun Heo
2 siblings, 0 replies; 4+ messages in thread
From: David Vernet @ 2024-08-08 17:00 UTC (permalink / raw)
To: Tejun Heo; +Cc: Phil Auld, linux-kernel, kernel-team
[-- Attachment #1: Type: text/plain, Size: 2437 bytes --]
On Wed, Aug 07, 2024 at 02:52:50PM -1000, Tejun Heo wrote:
Hi Tejun,
> sched_ext currently doesn't generate messages when the BPF scheduler is
> enabled and disabled unless there are errors. It is useful to have paper
> trail. Improve logging around enable/disable:
>
> - Generate info messages on enable and non-error disable.
>
> - Update error exit message formatting so that it's consistent with
> non-error message. Also, prefix ei->msg with the BPF scheduler's name to
> make it clear where the message is coming from.
>
> - Shorten scx_exit_reason() strings for SCX_EXIT_UNREG* for brevity and
> consistency.
>
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Suggested-by: Phil Auld <pauld@redhat.com>
> ---
> kernel/sched/ext.c | 21 +++++++++++++--------
> 1 file changed, 13 insertions(+), 8 deletions(-)
>
> diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
> index 60a7eb7d8a9e..eea2fda8e099 100644
> --- a/kernel/sched/ext.c
> +++ b/kernel/sched/ext.c
> @@ -4004,11 +4004,11 @@ static const char *scx_exit_reason(enum scx_exit_kind kind)
> {
> switch (kind) {
> case SCX_EXIT_UNREG:
> - return "Scheduler unregistered from user space";
> + return "unregistered from user space";
> case SCX_EXIT_UNREG_BPF:
> - return "Scheduler unregistered from BPF";
> + return "unregistered from BPF";
> case SCX_EXIT_UNREG_KERN:
> - return "Scheduler unregistered from the main kernel";
> + return "unregistered from the main kernel";
> case SCX_EXIT_SYSRQ:
> return "disabled by sysrq-S";
> case SCX_EXIT_ERROR:
> @@ -4126,14 +4126,17 @@ static void scx_ops_disable_workfn(struct kthread_work *work)
> percpu_up_write(&scx_fork_rwsem);
>
> if (ei->kind >= SCX_EXIT_ERROR) {
> - printk(KERN_ERR "sched_ext: BPF scheduler \"%s\" errored, disabling\n", scx_ops.name);
> + pr_err("sched_ext: BPF scheduler \"%s\" disabled (%s)\n",
> + scx_ops.name, ei->reason);
>
> - if (ei->msg[0] == '\0')
> - printk(KERN_ERR "sched_ext: %s\n", ei->reason);
> - else
> - printk(KERN_ERR "sched_ext: %s (%s)\n", ei->reason, ei->msg);
> + if (ei->msg[0] != '\0')
> + printk(KERN_ERR "sched_ext: %s: %s\n",
> + scx_ops.name, ei->msg);
Was it intentional to use pr_err() above, and printk() here? If not,
let's make them consistent?
Looks good otherwise.
Acked-by: David Vernet <void@manifault.com>
Thanks,
David
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^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH v2 sched_ext/for-6.12] sched_ext: Improve logging around enable/disable
2024-08-08 0:52 [PATCH sched_ext/for-6.12] sched_ext: Improve logging around enable/disable Tejun Heo
2024-08-08 12:38 ` Phil Auld
2024-08-08 17:00 ` David Vernet
@ 2024-08-08 23:47 ` Tejun Heo
2 siblings, 0 replies; 4+ messages in thread
From: Tejun Heo @ 2024-08-08 23:47 UTC (permalink / raw)
To: David Vernet, Phil Auld; +Cc: linux-kernel, kernel-team
From 344576fa6a69ce1292ef669c8d50c2088c36dc1e Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Wed, 7 Aug 2024 14:52:50 -1000
Subject: [PATCH] sched_ext: Improve logging around enable/disable
sched_ext currently doesn't generate messages when the BPF scheduler is
enabled and disabled unless there are errors. It is useful to have paper
trail. Improve logging around enable/disable:
- Generate info messages on enable and non-error disable.
- Update error exit message formatting so that it's consistent with
non-error message. Also, prefix ei->msg with the BPF scheduler's name to
make it clear where the message is coming from.
- Shorten scx_exit_reason() strings for SCX_EXIT_UNREG* for brevity and
consistency.
v2: Use pr_*() instead of KERN_* consistently. (David)
Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-by: Phil Auld <pauld@redhat.com>
Reviewed-by: Phil Auld <pauld@redhat.com>
Acked-by: David Vernet <void@manifault.com>
---
Applied to sched_ext/for-6.12 w/ the pr_err() update.
Thanks.
kernel/sched/ext.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index 17af9c46d891..143c4207a826 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -4013,11 +4013,11 @@ static const char *scx_exit_reason(enum scx_exit_kind kind)
{
switch (kind) {
case SCX_EXIT_UNREG:
- return "Scheduler unregistered from user space";
+ return "unregistered from user space";
case SCX_EXIT_UNREG_BPF:
- return "Scheduler unregistered from BPF";
+ return "unregistered from BPF";
case SCX_EXIT_UNREG_KERN:
- return "Scheduler unregistered from the main kernel";
+ return "unregistered from the main kernel";
case SCX_EXIT_SYSRQ:
return "disabled by sysrq-S";
case SCX_EXIT_ERROR:
@@ -4135,14 +4135,16 @@ static void scx_ops_disable_workfn(struct kthread_work *work)
percpu_up_write(&scx_fork_rwsem);
if (ei->kind >= SCX_EXIT_ERROR) {
- printk(KERN_ERR "sched_ext: BPF scheduler \"%s\" errored, disabling\n", scx_ops.name);
+ pr_err("sched_ext: BPF scheduler \"%s\" disabled (%s)\n",
+ scx_ops.name, ei->reason);
- if (ei->msg[0] == '\0')
- printk(KERN_ERR "sched_ext: %s\n", ei->reason);
- else
- printk(KERN_ERR "sched_ext: %s (%s)\n", ei->reason, ei->msg);
+ if (ei->msg[0] != '\0')
+ pr_err("sched_ext: %s: %s\n", scx_ops.name, ei->msg);
stack_trace_print(ei->bt, ei->bt_len, 2);
+ } else {
+ pr_info("sched_ext: BPF scheduler \"%s\" disabled (%s)\n",
+ scx_ops.name, ei->reason);
}
if (scx_ops.exit)
@@ -4817,6 +4819,8 @@ static int scx_ops_enable(struct sched_ext_ops *ops, struct bpf_link *link)
if (!(ops->flags & SCX_OPS_SWITCH_PARTIAL))
static_branch_enable(&__scx_switched_all);
+ pr_info("sched_ext: BPF scheduler \"%s\" enabled%s\n",
+ scx_ops.name, scx_switched_all() ? "" : " (partial)");
kobject_uevent(scx_root_kobj, KOBJ_ADD);
mutex_unlock(&scx_ops_enable_mutex);
--
2.46.0
^ permalink raw reply [flat|nested] 4+ messages in thread