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 53F31C433FE for ; Mon, 31 Jan 2022 16:33:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350217AbiAaQdq (ORCPT ); Mon, 31 Jan 2022 11:33:46 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:21761 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1380493AbiAaQdm (ORCPT ); Mon, 31 Jan 2022 11:33:42 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1643646821; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yS2LXvHJpQ6J5JWRMEEhchS65pUuAfYv0luhTwYX+Ho=; b=XnD85oe7daW6XOljNbzAK18e+Oz7ZKGRqmPkiiI1pMKRoYGQBFRPejPMkxYxP+jYEC6drP 3lj0LxpuFHTYUBFe9wZO1TFzliRJI2zEgSvlLtZw2InjT2NIsgm6wPxq0Q0P+k83zeIFaH mtnMx2a0k75j/PSfvb+nnnIRrLMBXpo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-652-ysRcGFu6Pn2U572AOTfgrQ-1; Mon, 31 Jan 2022 11:33:37 -0500 X-MC-Unique: ysRcGFu6Pn2U572AOTfgrQ-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 24C001091DA1; Mon, 31 Jan 2022 16:33:34 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.39.193.115]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2BB34798C6; Mon, 31 Jan 2022 16:33:27 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: Andrew Morton , Hugh Dickins , Linus Torvalds , David Rientjes , Shakeel Butt , John Hubbard , Jason Gunthorpe , Mike Kravetz , Mike Rapoport , Yang Shi , "Kirill A . Shutemov" , Matthew Wilcox , Vlastimil Babka , Jann Horn , Michal Hocko , Nadav Amit , Rik van Riel , Roman Gushchin , Andrea Arcangeli , Peter Xu , Donald Dutile , Christoph Hellwig , Oleg Nesterov , Jan Kara , Liang Zhang , linux-mm@kvack.org, David Hildenbrand Subject: [PATCH v3 9/9] mm/huge_memory: remove stale locking logic from __split_huge_pmd() Date: Mon, 31 Jan 2022 17:29:39 +0100 Message-Id: <20220131162940.210846-10-david@redhat.com> In-Reply-To: <20220131162940.210846-1-david@redhat.com> References: <20220131162940.210846-1-david@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Let's remove the stale logic that was required for reuse_swap_page(). Signed-off-by: David Hildenbrand --- mm/huge_memory.c | 32 +------------------------------- 1 file changed, 1 insertion(+), 31 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index a6dc5af1a763..cda88d8ac1bd 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2152,8 +2152,6 @@ void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, { spinlock_t *ptl; struct mmu_notifier_range range; - bool do_unlock_page = false; - pmd_t _pmd; mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, vma->vm_mm, address & HPAGE_PMD_MASK, @@ -2172,35 +2170,9 @@ void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, goto out; } -repeat: if (pmd_trans_huge(*pmd)) { - if (!page) { + if (!page) page = pmd_page(*pmd); - /* - * An anonymous page must be locked, to ensure that a - * concurrent reuse_swap_page() sees stable mapcount; - * but reuse_swap_page() is not used on shmem or file, - * and page lock must not be taken when zap_pmd_range() - * calls __split_huge_pmd() while i_mmap_lock is held. - */ - if (PageAnon(page)) { - if (unlikely(!trylock_page(page))) { - get_page(page); - _pmd = *pmd; - spin_unlock(ptl); - lock_page(page); - spin_lock(ptl); - if (unlikely(!pmd_same(*pmd, _pmd))) { - unlock_page(page); - put_page(page); - page = NULL; - goto repeat; - } - put_page(page); - } - do_unlock_page = true; - } - } if (PageMlocked(page)) clear_page_mlock(page); } else if (!(pmd_devmap(*pmd) || is_pmd_migration_entry(*pmd))) @@ -2208,8 +2180,6 @@ void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, __split_huge_pmd_locked(vma, pmd, range.start, freeze); out: spin_unlock(ptl); - if (do_unlock_page) - unlock_page(page); /* * No need to double call mmu_notifier->invalidate_range() callback. * They are 3 cases to consider inside __split_huge_pmd_locked(): -- 2.34.1