lkml.org 
[lkml]   [2023]   [Feb]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2] sched/debug: Put sched/domains files under the verbose flag
Hi Ingo, Peter,

On Fri, Jan 20, 2023 at 11:33:30AM -0500 Phil Auld wrote:
> The debug files under sched/domains can take a long time to regenerate,
> especially when updates are done one at a time. Move these files under
> the sched verbose debug flag. Allow changes to verbose to trigger
> generation of the files. This lets a user batch the updates but still
> have the information available. The detailed topology printk messages
> are also under verbose.
>
> Discussion that lead to this approach can be found in the link below.
>
> Simplified code to maintain use of debugfs bool routines suggested by
> Michael Ellerman <mpe@ellerman.id.au>.
>
> Signed-off-by: Phil Auld <pauld@redhat.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
> Cc: Valentin Schneider <vschneid@redhat.com>
> Cc: Vishal Chourasia <vishalc@linux.vnet.ibm.com>
> Cc: Vincent Guittot <vincent.guittot@linaro.org>
> Link: https://lore.kernel.org/all/Y01UWQL2y2r69sBX@li-05afa54c-330e-11b2-a85c-e3f3aa0db1e9.ibm.com/
> ---

Thoughts on this one?


Thanks,
Phil


>
> v2: fix comment typo and use cpumask_empty()
>
> kernel/sched/debug.c | 52 +++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 49 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
> index 1637b65ba07a..0b2340a79b65 100644
> --- a/kernel/sched/debug.c
> +++ b/kernel/sched/debug.c
> @@ -280,6 +280,45 @@ static const struct file_operations sched_dynamic_fops = {
>
> __read_mostly bool sched_debug_verbose;
>
> +#ifdef CONFIG_SMP
> +static struct dentry *sd_dentry;
> +
> +
> +static ssize_t sched_verbose_write(struct file *filp, const char __user *ubuf,
> + size_t cnt, loff_t *ppos)
> +{
> + ssize_t result;
> + bool orig;
> +
> + cpus_read_lock();
> + mutex_lock(&sched_domains_mutex);
> +
> + orig = sched_debug_verbose;
> + result = debugfs_write_file_bool(filp, ubuf, cnt, ppos);
> +
> + if (sched_debug_verbose && !orig)
> + update_sched_domain_debugfs();
> + else if (!sched_debug_verbose && orig) {
> + debugfs_remove(sd_dentry);
> + sd_dentry = NULL;
> + }
> +
> + mutex_unlock(&sched_domains_mutex);
> + cpus_read_unlock();
> +
> + return result;
> +}
> +#else
> +#define sched_verbose_write debugfs_write_file_bool
> +#endif
> +
> +static const struct file_operations sched_verbose_fops = {
> + .read = debugfs_read_file_bool,
> + .write = sched_verbose_write,
> + .open = simple_open,
> + .llseek = default_llseek,
> +};
> +
> static const struct seq_operations sched_debug_sops;
>
> static int sched_debug_open(struct inode *inode, struct file *filp)
> @@ -303,7 +342,7 @@ static __init int sched_init_debug(void)
> debugfs_sched = debugfs_create_dir("sched", NULL);
>
> debugfs_create_file("features", 0644, debugfs_sched, NULL, &sched_feat_fops);
> - debugfs_create_bool("verbose", 0644, debugfs_sched, &sched_debug_verbose);
> + debugfs_create_file_unsafe("verbose", 0644, debugfs_sched, &sched_debug_verbose, &sched_verbose_fops);
> #ifdef CONFIG_PREEMPT_DYNAMIC
> debugfs_create_file("preempt", 0644, debugfs_sched, NULL, &sched_dynamic_fops);
> #endif
> @@ -345,7 +384,6 @@ late_initcall(sched_init_debug);
> #ifdef CONFIG_SMP
>
> static cpumask_var_t sd_sysctl_cpus;
> -static struct dentry *sd_dentry;
>
> static int sd_flags_show(struct seq_file *m, void *v)
> {
> @@ -402,15 +440,23 @@ void update_sched_domain_debugfs(void)
> if (!debugfs_sched)
> return;
>
> + if (!sched_debug_verbose)
> + return;
> +
> if (!cpumask_available(sd_sysctl_cpus)) {
> if (!alloc_cpumask_var(&sd_sysctl_cpus, GFP_KERNEL))
> return;
> cpumask_copy(sd_sysctl_cpus, cpu_possible_mask);
> }
>
> - if (!sd_dentry)
> + if (!sd_dentry) {
> sd_dentry = debugfs_create_dir("domains", debugfs_sched);
>
> + /* rebuild sd_sysctl_cpus if empty since it gets cleared below */
> + if (cpumask_empty(sd_sysctl_cpus))
> + cpumask_copy(sd_sysctl_cpus, cpu_online_mask);
> + }
> +
> for_each_cpu(cpu, sd_sysctl_cpus) {
> struct sched_domain *sd;
> struct dentry *d_cpu;
> --
> 2.31.1
>

--

\
 
 \ /
  Last update: 2023-03-27 00:15    [W:0.267 / U:0.660 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site