linux-kernel - Re: [PATCH v5 15/20] x86/resctrl: Assign/unassign counters by default when ABMC is enabled

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Message-ID: <CALPaoCi2dKoqGEPO6JDLG-4ce8y=uAg-9znQfNo6xg_0k=TknA@mail.gmail.com>
Date: Fri, 26 Jul 2024 16:22:43 -0700
From: Peter Newman <peternewman@...gle.com>
To: Babu Moger <babu.moger@....com>
Cc: corbet@....net, fenghua.yu@...el.com, reinette.chatre@...el.com, 
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Subject: Re: [PATCH v5 15/20] x86/resctrl: Assign/unassign counters by default
 when ABMC is enabled

Hi Babu,

On Wed, Jul 3, 2024 at 2:50 PM Babu Moger <babu.moger@....com> wrote:

> @@ -3894,6 +3956,17 @@ static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,
>         if (ret)
>                 goto out_closid_free;
>
> +       /*
> +        * Assign the counters if ABMC is already enabled.
> +        * With the limited number of counters, there can be cases
> +        * only on assignment succeed. It is not required to fail
> +        * here in that case. Users have the option to assign the
> +        * counter later.
> +        */
> +
> +       if (rdtgroup_assign_cntrs(rdtgrp) < 0)
> +               rdt_last_cmd_puts("Monitor assignment failed\n");

Supposing rdtgroup_init_alloc() below fails, would you want to release
the counters allocated here?

> +
>         kernfs_activate(rdtgrp->kn);
>
>         ret = rdtgroup_init_alloc(rdtgrp);

-Peter