linux-kernel - [PATCH 1/2] x86/resctrl: Fix repeating rdtgroup mode initialization

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Date:   Wed, 10 Apr 2019 03:53:49 +0800
From:   Xiaochen Shen <xiaochen.shen@...el.com>
To:     tglx@...utronix.de, mingo@...hat.com, bp@...en8.de, hpa@...or.com,
        tony.luck@...el.com, fenghua.yu@...el.com,
        reinette.chatre@...el.com
Cc:     x86@...nel.org, linux-kernel@...r.kernel.org, pei.p.jia@...el.com,
        xiaochen.shen@...el.com
Subject: [PATCH 1/2] x86/resctrl: Fix repeating rdtgroup mode initialization

When cache allocation is supported and the user creates a new resctrl
resource group the allocations of the new resource group are initialized
to all regions that it can possibly use. At this time these regions are
all that are shareable by other resource groups as well as regions that
are not currently used. The new resource group's mode is also
initialized to reflect this initialization and set to "shareable".

The new resource group's mode is currently repeatedly initialized within
the loop that configures the hardware with the resource group's default
allocations.

Move the initialization of the resource group's mode outside the
hardware configuration loop. The resource group's mode is now
initialized only once as the final step to reflect that its configured
allocations are "shareable".

Fixes: 95f0b77efa57 ("x86/intel_rdt: Initialize new resource group with sane defaults")
Signed-off-by: Xiaochen Shen <xiaochen.shen@...el.com>
Acked-by: Reinette Chatre <reinette.chatre@...el.com>
Reviewed-by: Fenghua Yu <fenghua.yu@...el.com>
---
 arch/x86/kernel/cpu/resctrl/rdtgroup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 54b9eef..08e0333 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -2610,8 +2610,8 @@ static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
 			rdt_last_cmd_puts("Failed to initialize allocations\n");
 			return ret;
 		}
-		rdtgrp->mode = RDT_MODE_SHAREABLE;
 	}
+	rdtgrp->mode = RDT_MODE_SHAREABLE;

 	return 0;
 }
-- 
1.8.3.1