linux-kernel - Re: [PATCH 15/21] x86/intel

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Message-ID: <alpine.DEB.2.20.1707021509130.2296@nanos>
Date:   Sun, 2 Jul 2017 15:16:24 +0200 (CEST)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Vikas Shivappa <vikas.shivappa@...ux.intel.com>
cc:     x86@...nel.org, linux-kernel@...r.kernel.org, hpa@...or.com,
        peterz@...radead.org, ravi.v.shankar@...el.com,
        vikas.shivappa@...el.com, tony.luck@...el.com,
        fenghua.yu@...el.com, andi.kleen@...el.com
Subject: Re: [PATCH 15/21] x86/intel_rdt/cqm: Add rmdir support

On Mon, 26 Jun 2017, Vikas Shivappa wrote:

> Resource groups (ctrl_mon and monitor groups) are represented by
> directories in resctrl fs. Add support to remove the directories.

Again. Please split that patch into two parts; seperate ctrl stuff from rmdir and
then add monitoring support.

> +	rdtgrp->flags = RDT_DELETED;
> +	free_rmid(rdtgrp->rmid);
> +
> +	/*
> +	 * Remove your rmid from the parent ctrl groups list

You are not removing a rmid. You remove the group from the parents group
list. Please be more accurate with your comments. Wrong comments are worse
than no comments.

> +	WARN_ON(list_empty(&prdtgrp->crdtgrp_list));
> +	list_del(&rdtgrp->crdtgrp_list);

> +static int rdtgroup_rmdir_ctrl(struct kernfs_node *kn, struct rdtgroup *rdtgrp)
> +{
> +	int cpu, closid = rdtgroup_default.closid;
> +	struct rdtgroup *entry, *tmp;
> +	struct list_head *llist;

*head please.

> +	cpumask_var_t tmpmask;
> +
> +	if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
> +		return -ENOMEM;

Allocation/free can be done at the call site for both functions.

> +static int rdtgroup_rmdir(struct kernfs_node *kn)
> +{
> +	struct kernfs_node *parent_kn = kn->parent;
> +	struct rdtgroup *rdtgrp;
> +	int ret = 0;
> +
> +	rdtgrp = rdtgroup_kn_lock_live(kn);
> +	if (!rdtgrp) {
> +		ret = -EPERM;
> +		goto out;
> +	}
> +
> +	if (rdtgrp->type == RDTCTRL_GROUP && parent_kn == rdtgroup_default.kn)
> +		ret = rdtgroup_rmdir_ctrl(kn, rdtgrp);
> +	else if (rdtgrp->type == RDTMON_GROUP &&
> +		 !strcmp(parent_kn->name, "mon_groups"))
> +		ret = rdtgroup_rmdir_mon(kn, rdtgrp);
> +	else
> +		ret = -EPERM;

Like in the other patch, please makes this parseable.

Thanks,

	tglx