From patchwork Fri Aug 2 15:55:18 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13751728 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D519B1E486C for ; Fri, 2 Aug 2024 15:56:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722614176; cv=none; b=Jl/KHbbSTEXiQ7Am1cS73Odv9Mzxz3zR3m/lwvbPRgC3j140Msxiz2amRS9sbxuN4btZwiOmt/AEEMArVUFVHR8aisGu+DQPa9mXvpPkaQeonFxTaIWyEdQO7jOTje0AAS+f70f3gO9qFUvUyWAiaxRjP2FFKoGTYTdtU34uTCU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722614176; c=relaxed/simple; bh=P92AymmJj/Ft8pl2A+91m7BSNQa3s/9+AJd/Q8AkboU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=G7OK6gt9CI/qKCUFQ+9V1jhTm3ymEyoGjbsdAFXySCwlM3Jy7Yn/olKjLO0B0c3hyPES9QSvCA0GYBtkY4N2gKbaP3+16/bgrHOvNjUIK9gfcge75TkgfbmYEdHYW0iv+9KXEsLwowdXVzRJiFEfix6JDWNo7r5RhNKdKBRboVk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=OubIpU+N; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="OubIpU+N" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1722614174; 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=Dsokb2QZ1A8J7FAYTpU1vDg99kVkubfGaPDc1WAA3q4=; b=OubIpU+NhCmv6kWJXFG8SkcZ52HY1WtLa9Sh+cdgbI9vntamICNshmtNgdrMw0WXG1SAVb 0lT7FCOD+enmN4xzYXtBJeqk6tXnVFlLZ14gmlYHl6yCkALd3wsmhGcl4CW6eWKhwn7rbP R8CGFIsmc6Qmuko9WC6fzXHnZz8X1Kw= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-318-NNjgzyEROca_nRik9KEcaw-1; Fri, 02 Aug 2024 11:56:08 -0400 X-MC-Unique: NNjgzyEROca_nRik9KEcaw-1 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4CD5B19560B1; Fri, 2 Aug 2024 15:56:06 +0000 (UTC) Received: from t14s.redhat.com (unknown [10.39.192.113]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 241AD300018D; Fri, 2 Aug 2024 15:55:59 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, linux-doc@vger.kernel.org, kvm@vger.kernel.org, linux-s390@vger.kernel.org, linux-fsdevel@vger.kernel.org, David Hildenbrand , Andrew Morton , "Matthew Wilcox (Oracle)" , Jonathan Corbet , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Sven Schnelle , Gerald Schaefer Subject: [PATCH v1 05/11] mm/ksm: convert get_mergeable_page() from follow_page() to folio_walk Date: Fri, 2 Aug 2024 17:55:18 +0200 Message-ID: <20240802155524.517137-6-david@redhat.com> In-Reply-To: <20240802155524.517137-1-david@redhat.com> References: <20240802155524.517137-1-david@redhat.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Let's use folio_walk instead, for example avoiding taking temporary folio references if the folio does not even apply and getting rid of one more follow_page() user. Note that zeropages obviously don't apply: old code could just have specified FOLL_DUMP. Anon folios are never secretmem, so we don't care about losing the check in follow_page(). Signed-off-by: David Hildenbrand --- mm/ksm.c | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-) diff --git a/mm/ksm.c b/mm/ksm.c index 14d9e53b1ec2..742b005f3f77 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -767,26 +767,28 @@ static struct page *get_mergeable_page(struct ksm_rmap_item *rmap_item) struct mm_struct *mm = rmap_item->mm; unsigned long addr = rmap_item->address; struct vm_area_struct *vma; - struct page *page; + struct page *page = NULL; + struct folio_walk fw; + struct folio *folio; mmap_read_lock(mm); vma = find_mergeable_vma(mm, addr); if (!vma) goto out; - page = follow_page(vma, addr, FOLL_GET); - if (IS_ERR_OR_NULL(page)) - goto out; - if (is_zone_device_page(page)) - goto out_putpage; - if (PageAnon(page)) { + folio = folio_walk_start(&fw, vma, addr, 0); + if (folio) { + if (!folio_is_zone_device(folio) && + folio_test_anon(folio)) { + folio_get(folio); + page = fw.page; + } + folio_walk_end(&fw, vma); + } +out: + if (page) { flush_anon_page(vma, page, addr); flush_dcache_page(page); - } else { -out_putpage: - put_page(page); -out: - page = NULL; } mmap_read_unlock(mm); return page;