From: Tejun Heo <tj@kernel.org> mainline inclusion from mainline-v6.12-rc1 commit 344576fa6a69ce1292ef669c8d50c2088c36dc1e category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IDC9YK Reference: https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commi... -------------------------------- 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> Signed-off-by: Zicheng Qu <quzicheng@huawei.com> --- 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 61cb72a64b0f..6bf471dd5d3f 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -4022,11 +4022,11 @@ 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: @@ -4144,14 +4144,16 @@ 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) @@ -4826,6 +4828,8 @@ static int scx_ops_enable(struct sched_ext_ops *ops) 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); -- 2.34.1