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From:   Rik van Riel <riel@surriel.com>
To:     linux-kernel@vger.kernel.org
Cc:     kernel-team@fb.com, peterz@infradead.org, luto@kernel.org,
        x86@kernel.org, vkuznets@redhat.com, mingo@kernel.org,
        efault@gmx.de, dave.hansen@intel.com, will.daecon@arm.com,
        catalin.marinas@arm.com, benh@kernel.crashing.org,
        Rik van Riel <riel@surriel.com>
Subject: [PATCH 08/10] arch,mm: add config variable to skip lazy TLB mm refcounting
Date:   Sat, 28 Jul 2018 17:53:55 -0400
Message-Id: <20180728215357.3249-9-riel@surriel.com>
In-Reply-To: <20180728215357.3249-1-riel@surriel.com>
References: <20180728215357.3249-1-riel@surriel.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Add a config variable indicating that this architecture does not require
lazy TLB mm refcounting, because lazy TLB mms get shot down instantly
at exit_mmap time.

Signed-off-by: Rik van Riel <riel@surriel.com>
---
 arch/Kconfig | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/Kconfig b/arch/Kconfig
index 1aa59063f1fd..1baf1a176dbf 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -237,6 +237,10 @@ config ARCH_HAS_FORTIFY_SOURCE
 config ARCH_HAS_SET_MEMORY
 	bool
 
+# Select if arch shoots down lazy TLB mms at exit time, instead of refcounting
+config ARCH_NO_ACTIVE_MM_REFCOUNTING
+	bool
+
 # Select if arch init_task must go in the __init_task_data section
 config ARCH_TASK_STRUCT_ON_STACK
        bool
-- 
2.14.4