From nobody Fri Apr 3 09:58:34 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 90074C6FA82 for ; Thu, 15 Sep 2022 03:16:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230179AbiIODQO (ORCPT ); Wed, 14 Sep 2022 23:16:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55476 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229495AbiIODQL (ORCPT ); Wed, 14 Sep 2022 23:16:11 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5314B910BB for ; Wed, 14 Sep 2022 20:16:09 -0700 (PDT) Received: from dggpemm500024.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4MSj1J5yqJzmV89; Thu, 15 Sep 2022 11:12:20 +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; Thu, 15 Sep 2022 11:16:07 +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; Thu, 15 Sep 2022 11:16:06 +0800 From: Liu Shixin To: Seth Jennings , Dan Streetman , Vitaly Wool , Andrew Morton , Nathan Chancellor , "Christoph Hellwig" CC: , , Liu Shixin , Kefeng Wang Subject: [PATCH v5 2/5] Revert "frontswap: simplify frontswap_register_ops" Date: Thu, 15 Sep 2022 11:50:00 +0800 Message-ID: <20220915035003.3347466-3-liushixin2@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220915035003.3347466-1-liushixin2@huawei.com> References: <20220915035003.3347466-1-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 | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) diff --git a/mm/frontswap.c b/mm/frontswap.c index 279e55b4ed87..aa3a1e3ddf91 100644 --- a/mm/frontswap.c +++ b/mm/frontswap.c @@ -96,11 +96,53 @@ static inline void inc_frontswap_invalidates(void) { } */ int frontswap_register_ops(const struct frontswap_ops *ops) { + DECLARE_BITMAP(a, MAX_SWAPFILES); + DECLARE_BITMAP(b, MAX_SWAPFILES); + struct swap_info_struct *si; + unsigned int i; + if (frontswap_ops) return -EINVAL; =20 + 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); + frontswap_ops =3D ops; 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); + } + } + return 0; } =20 --=20 2.25.1