[Devel] [PATCH rh7 02/11] ub: zap show_ub_mem

[Konstantin Khorenko]

On 05/20/2015 12:00 PM, Vladimir Davydov wrote:
> It is called by the showmem sysctl. Hell knows why it was added and who
> would ever used it.
It's not about sysctl, but about sysrq and we used it heavily until we start getting crash dumps from most of nodes.
=> you forgot to get rid of other parts of that as well:

static struct sysrq_key_op sysrq_unrt_op = {
        .handler        = sysrq_handle_unrt,
        .help_msg       = "nice-all-RT-tasks(n)",
        .action_msg     = "Nice All RT Tasks",
        .enable_mask    = SYSRQ_ENABLE_RTNICE,
};
...
static struct sysrq_key_op *sysrq_key_table[36] = {
...
        &sysrq_showmem_op,              /* m */

Volodya, please, make the patch complete.


Vasya, do we still consider Alt+SysRQ+m useful?
i tend to agree to drop it for now.

> Anyways, all this info is in memcg now, so zap it.
> If anyone needs it one day, which I doubt, it will have to be
> reimplemented in the scope of memcg.
> 
> Signed-off-by: Vladimir Davydov <vdavydov at parallels.com>
> ---
>  drivers/tty/sysrq.c  |    7 -------
>  include/bc/vmpages.h |    3 ---
>  kernel/bc/vm_pages.c |   29 -----------------------------
>  3 files changed, 39 deletions(-)
> 
> diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
> index 069928f0a814..fe0b813ee215 100644
> --- a/drivers/tty/sysrq.c
> +++ b/drivers/tty/sysrq.c
> @@ -313,13 +313,6 @@ static struct sysrq_key_op sysrq_ftrace_dump_op = {
>  
>  static void sysrq_handle_showmem(int key)
>  {
> -	struct user_beancounter *ub;
> -
> -	rcu_read_lock();
> -	for_each_beancounter(ub)
> -		show_ub_mem(ub);
> -	rcu_read_unlock();
> -
>  	show_mem(0);
>  }
>  static struct sysrq_key_op sysrq_showmem_op = {
> diff --git a/include/bc/vmpages.h b/include/bc/vmpages.h
> index 4833ef8a08bf..bf63b885441c 100644
> --- a/include/bc/vmpages.h
> +++ b/include/bc/vmpages.h
> @@ -47,7 +47,4 @@ UB_DECLARE_FUNC(int, ub_lockedshm_charge(struct shmem_inode_info *shi,
>  UB_DECLARE_VOID_FUNC(ub_lockedshm_uncharge(struct shmem_inode_info *shi,
>  			unsigned long size))
>  
> -void __show_ub_mem(struct user_beancounter *ub);
> -void show_ub_mem(struct user_beancounter *ub);
> -
>  #endif /* __UB_PAGES_H_ */
> diff --git a/kernel/bc/vm_pages.c b/kernel/bc/vm_pages.c
> index bc1a1d7c7fff..b1eedd29e17f 100644
> --- a/kernel/bc/vm_pages.c
> +++ b/kernel/bc/vm_pages.c
> @@ -270,35 +270,6 @@ static void __exit fini_vmguar_notifier(void)
>  module_init(init_vmguar_notifier);
>  module_exit(fini_vmguar_notifier);
>  
> -static void __show_one_resource(const char *name, struct ubparm *parm)
> -{
> -	if (parm->limit == UB_MAXVALUE)
> -		printk("%s: %lu / inf [%lu] ", name,
> -				parm->held, parm->failcnt);
> -	else
> -		printk("%s: %lu / %lu [%lu] ", name,
> -				parm->held, parm->limit, parm->failcnt);
> -}
> -
> -void __show_ub_mem(struct user_beancounter *ub)
> -{
> -	__show_one_resource("RAM", ub->ub_parms + UB_PHYSPAGES);
> -	__show_one_resource("SWAP", ub->ub_parms + UB_SWAPPAGES);
> -	__show_one_resource("KMEM", ub->ub_parms + UB_KMEMSIZE);
> -	__show_one_resource("DCSZ", ub->ub_parms + UB_DCACHESIZE);
> -	__show_one_resource("OOMG", ub->ub_parms + UB_OOMGUARPAGES);
> -
> -	printk("Dirty %lu Wback %lu\n",
> -			ub_stat_get(ub, dirty_pages),
> -			ub_stat_get(ub, writeback_pages));
> -}
> -
> -void show_ub_mem(struct user_beancounter *ub)
> -{
> -	printk(KERN_INFO "UB-%s-Mem-Info:\n", ub->ub_name);
> -	__show_ub_mem(ub);
> -}
> -
>  #ifdef CONFIG_PROC_FS
>  static int bc_vmaux_show(struct seq_file *f, void *v)
>  {
>