linux-kernel - Re: [PATCH v23 14/19] x86/resctrl: Handle removing directories in Sub-NUMA Cluster (SNC) mode

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Date: Tue, 2 Jul 2024 10:16:39 -0700
From: Tony Luck <tony.luck@...el.com>
To: Borislav Petkov <bp@...en8.de>
Cc: Fenghua Yu <fenghua.yu@...el.com>,
	Reinette Chatre <reinette.chatre@...el.com>,
	Maciej Wieczor-Retman <maciej.wieczor-retman@...el.com>,
	Peter Newman <peternewman@...gle.com>,
	James Morse <james.morse@....com>, Babu Moger <babu.moger@....com>,
	Drew Fustini <dfustini@...libre.com>,
	Dave Martin <Dave.Martin@....com>, x86@...nel.org,
	linux-kernel@...r.kernel.org, patches@...ts.linux.dev
Subject: Re: [PATCH v23 14/19] x86/resctrl: Handle removing directories in
 Sub-NUMA Cluster (SNC) mode

On Tue, Jul 02, 2024 at 10:53:37AM +0200, Borislav Petkov wrote:
> On Fri, Jun 28, 2024 at 02:56:14PM -0700, Tony Luck wrote:
...
> ... and this are almost identical hunks.
> 
> Why isn't there a helper which gets called here?

A helper will avoid this duplication. Draft below. Is this
what you want? Is the function name OK. I wasn't sure if the
"mon" looked better at the beginning. Or as rmdir_one_mon_subdir()

I've also fixed up part 17 to use msr_clear_bit()

Are you still digging through the patches?

-Tony

static void mon_rmdir_one_subdir(struct kernfs_node *pkn, char *name, char *subname)
{
	struct kernfs_node *kn;

	kn = kernfs_find_and_get(pkn, name);
	if (!kn)
		return;
	kernfs_put(kn);

	if (kn->dir.subdirs <= 1)
		kernfs_remove(kn);
	else
		kernfs_remove_by_name(kn, subname);
}

/*
 * Remove all subdirectories of mon_data of ctrl_mon groups
 * and monitor groups for the given domain.
 * Remove files and directories containing "sum" of domain data
 * when last domain being summed is removed.
 */
static void rmdir_mondata_subdir_allrdtgrp(struct rdt_resource *r,
					   struct rdt_mon_domain *d)
{
	struct rdtgroup *prgrp, *crgrp;
	char subname[32];
	bool snc_mode;
	char name[32];

	snc_mode = r->mon_scope == RESCTRL_L3_NODE;
	sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci->id : d->hdr.id);
	if (snc_mode)
		sprintf(subname, "mon_sub_%s_%02d", r->name, d->hdr.id);

	list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
		mon_rmdir_one_subdir(prgrp->mon.mon_data_kn, name, subname);

		list_for_each_entry(crgrp, &prgrp->mon.crdtgrp_list, mon.crdtgrp_list)
			mon_rmdir_one_subdir(crgrp->mon.mon_data_kn, name, subname);
	}
}