linux-kernel - [PATCH v2 11/23] x86/resctrl: Remove set_mba

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Message-Id: <20211001160302.31189-12-james.morse@arm.com>
Date:   Fri,  1 Oct 2021 16:02:50 +0000
From:   James Morse <james.morse@....com>
To:     x86@...nel.org, linux-kernel@...r.kernel.org
Cc:     Fenghua Yu <fenghua.yu@...el.com>,
        Reinette Chatre <reinette.chatre@...el.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        H Peter Anvin <hpa@...or.com>,
        Babu Moger <Babu.Moger@....com>,
        James Morse <james.morse@....com>,
        shameerali.kolothum.thodi@...wei.com,
        Jamie Iles <jamie@...iainc.com>,
        D Scott Phillips OS <scott@...amperecomputing.com>,
        lcherian@...vell.com, bobo.shaobowang@...wei.com,
        tan.shaopeng@...itsu.com
Subject: [PATCH v2 11/23] x86/resctrl: Remove set_mba_sc()s control array re-initialisation

set_mba_sc() is called by rdt_enable_ctx() during mount()
and rdt_kill_sb(). It currently re-initialises the arch code's control
value array.

These values are already set to their default when the domain is created,
and when rdt_kill_sb() is called, (via reset_all_ctrls()). set_mba_sc()s
extra call to setup_default_ctrlval() isn't needed as the values are
already at their defaults due to the creation of the domain, or reset
during umount().

Remove it.

Signed-off-by: James Morse <james.morse@....com>
---
 arch/x86/kernel/cpu/resctrl/rdtgroup.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 52a7accbff8b..069c209be1d5 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1956,18 +1956,12 @@ static void mba_sc_destroy(struct rdt_resource *r)
 static int set_mba_sc(bool mba_sc)
 {
 	struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl;
-	struct rdt_hw_domain *hw_dom;
-	struct rdt_domain *d;
 
 	if (!is_mbm_enabled() || !is_mba_linear() ||
 	    mba_sc == is_mba_sc(r))
 		return -EINVAL;
 
 	r->membw.mba_sc = mba_sc;
-	list_for_each_entry(d, &r->domains, list) {
-		hw_dom = resctrl_to_arch_dom(d);
-		setup_default_ctrlval(r, hw_dom->ctrl_val);
-	}
 
 	if (is_mba_sc(r))
 		return mba_sc_allocate(r);
-- 
2.30.2