From nobody Thu Apr 9 13:58:41 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 55BBDECAAD4 for ; Mon, 29 Aug 2022 12:58:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229507AbiH2M6K (ORCPT ); Mon, 29 Aug 2022 08:58:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230343AbiH2M4h (ORCPT ); Mon, 29 Aug 2022 08:56:37 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0BDEA1A83C for ; Mon, 29 Aug 2022 05:48:38 -0700 (PDT) Received: from dggpemm500024.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4MGVWt2QRCzkWl8; Mon, 29 Aug 2022 20:44:58 +0800 (CST) Received: from dggpemm100009.china.huawei.com (7.185.36.113) by dggpemm500024.china.huawei.com (7.185.36.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Mon, 29 Aug 2022 20:48:35 +0800 Received: from huawei.com (10.175.113.32) by dggpemm100009.china.huawei.com (7.185.36.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Mon, 29 Aug 2022 20:48:34 +0800 From: Liu Shixin To: Seth Jennings , Dan Streetman , Vitaly Wool , Andrew Morton , Nathan Chancellor , "Christoph Hellwig" CC: , , Liu Shixin , Kefeng Wang Subject: [PATCH -next v4 3/6] Revert "frontswap: simplify frontswap_register_ops" Date: Mon, 29 Aug 2022 21:22:59 +0800 Message-ID: <20220829132302.3367054-4-liushixin2@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220829132302.3367054-1-liushixin2@huawei.com> References: <20220829132302.3367054-1-liushixin2@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.113.32] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpemm100009.china.huawei.com (7.185.36.113) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This reverts commit f328c1d16e4c764992895ac9c9425cea861b2ca0. Since we are supported to delay zswap initializaton, we need to invoke ops->init for the swap device which is already online when register backend. Signed-off-by: Liu Shixin --- mm/frontswap.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/mm/frontswap.c b/mm/frontswap.c index 8d644f56a1d2..555e78f9529d 100644 --- a/mm/frontswap.c +++ b/mm/frontswap.c @@ -99,6 +99,25 @@ static inline void inc_frontswap_invalidates(void) { } */ void frontswap_register_ops(struct frontswap_ops *ops) { + DECLARE_BITMAP(a, MAX_SWAPFILES); + DECLARE_BITMAP(b, MAX_SWAPFILES); + struct swap_info_struct *si; + unsigned int i; + + bitmap_zero(a, MAX_SWAPFILES); + bitmap_zero(b, MAX_SWAPFILES); + + spin_lock(&swap_lock); + plist_for_each_entry(si, &swap_active_head, list) { + if (!WARN_ON(!si->frontswap_map)) + __set_bit(si->type, a); + } + spin_unlock(&swap_lock); + + /* the new ops needs to know the currently active swap devices */ + for_each_set_bit(i, a, MAX_SWAPFILES) + ops->init(i); + /* * Setting frontswap_ops must happen after the ops->init() calls * above; cmpxchg implies smp_mb() which will ensure the init is @@ -109,6 +128,28 @@ void frontswap_register_ops(struct frontswap_ops *ops) } while (cmpxchg(&frontswap_ops, ops->next, ops) !=3D ops->next); =20 static_branch_inc(&frontswap_enabled_key); + + spin_lock(&swap_lock); + plist_for_each_entry(si, &swap_active_head, list) { + if (si->frontswap_map) + __set_bit(si->type, b); + } + spin_unlock(&swap_lock); + + /* + * On the very unlikely chance that a swap device was added or + * removed between setting the "a" list bits and the ops init + * calls, we re-check and do init or invalidate for any changed + * bits. + */ + if (unlikely(!bitmap_equal(a, b, MAX_SWAPFILES))) { + for (i =3D 0; i < MAX_SWAPFILES; i++) { + if (!test_bit(i, a) && test_bit(i, b)) + ops->init(i); + else if (test_bit(i, a) && !test_bit(i, b)) + ops->invalidate_area(i); + } + } } =20 /* --=20 2.25.1