From mboxrd@z Thu Jan 1 00:00:00 1970 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 3EFE0C433EF for ; Sat, 22 Jan 2022 06:15:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233477AbiAVGPG (ORCPT ); Sat, 22 Jan 2022 01:15:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57654 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233480AbiAVGPG (ORCPT ); Sat, 22 Jan 2022 01:15:06 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1EDD0C06173B for ; Fri, 21 Jan 2022 22:15:06 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B181361148 for ; Sat, 22 Jan 2022 06:15:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B6058C004E1; Sat, 22 Jan 2022 06:15:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1642832105; bh=CjdfayaxQpo4siA/aoCkWt4E8aKCKMd7twpl/LcaJh0=; h=Date:From:To:Subject:In-Reply-To:From; b=Q+FM57iqcXQiBzXZfddSHdmxDY21KUaDzbY9pYpFgI0VQ6FmhOT47VQS1snl5ae0z JN0BKJpF1SmyU2zCZ4WY3hYDuBHTEhfXZB9b5PpyPYZLcqdTkS/PWAeWAjexf2ops8 KGUEaBIUZjOi8cWPFjoPFNBUuePqaM8oCODZ804s= Date: Fri, 21 Jan 2022 22:15:04 -0800 From: Andrew Morton To: akpm@linux-foundation.org, ddstreet@ieee.org, geert@linux-m68k.org, hch@lst.de, hughd@google.com, jgross@suse.com, Konrad.wilk@oracle.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, sjenning@redhat.com, torvalds@linux-foundation.org, vitaly.wool@konsulko.com, willy@infradead.org Subject: [patch 66/69] frontswap: simplify frontswap_register_ops Message-ID: <20220122061504.4JqqECbOV%akpm@linux-foundation.org> In-Reply-To: <20220121221021.60533b009c357d660791476e@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Christoph Hellwig Subject: frontswap: simplify frontswap_register_ops Given that frontswap_register_ops must be called from built-in code, there is no need to handle the case of swapfiles coming online before or during it, so delete the code that deals with that case. Link: https://lkml.kernel.org/r/20211224062246.1258487-11-hch@lst.de Signed-off-by: Christoph Hellwig Reviewed-by: Juergen Gross Cc: Dan Streetman Cc: Geert Uytterhoeven Cc: Hugh Dickins Cc: Konrad Rzeszutek Wilk Cc: Matthew Wilcox (Oracle) Cc: Seth Jennings Cc: Vitaly Wool Signed-off-by: Andrew Morton --- mm/frontswap.c | 41 ----------------------------------------- 1 file changed, 41 deletions(-) --- a/mm/frontswap.c~frontswap-simplify-frontswap_register_ops +++ a/mm/frontswap.c @@ -99,25 +99,6 @@ static inline void inc_frontswap_invalid */ 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 @@ -128,28 +109,6 @@ void frontswap_register_ops(struct front } while (cmpxchg(&frontswap_ops, ops->next, ops) != ops->next); 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 = 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); - } - } } /* _