From patchwork Tue Mar 13 21:45:50 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Igor Stoppa X-Patchwork-Id: 10280935 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 1C3C9602C2 for ; Tue, 13 Mar 2018 21:50:48 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0ED182853A for ; Tue, 13 Mar 2018 21:50:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 03AD428565; Tue, 13 Mar 2018 21:50:48 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8F0882853A for ; Tue, 13 Mar 2018 21:50:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753075AbeCMVuq (ORCPT ); Tue, 13 Mar 2018 17:50:46 -0400 Received: from lhrrgout.huawei.com ([194.213.3.17]:29180 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753069AbeCMVup (ORCPT ); Tue, 13 Mar 2018 17:50:45 -0400 Received: from LHREML711-CAH.china.huawei.com (unknown [172.18.7.108]) by Forcepoint Email with ESMTP id ADA3A334A1AA1; Tue, 13 Mar 2018 21:50:41 +0000 (GMT) Received: from localhost.localdomain (10.122.225.51) by smtpsuk.huawei.com (10.201.108.34) with Microsoft SMTP Server (TLS) id 14.3.382.0; Tue, 13 Mar 2018 21:50:33 +0000 From: Igor Stoppa To: , , , , CC: , , , , , Igor Stoppa Subject: [PATCH 4/8] struct page: add field for vm_struct Date: Tue, 13 Mar 2018 23:45:50 +0200 Message-ID: <20180313214554.28521-5-igor.stoppa@huawei.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20180313214554.28521-1-igor.stoppa@huawei.com> References: <20180313214554.28521-1-igor.stoppa@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.122.225.51] X-CFilter-Loop: Reflected Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP When a page is used for virtual memory, it is often necessary to obtain a handler to the corresponding vm_struct, which refers to the virtually continuous area generated when invoking vmalloc. The struct page has a "mapping" field, which can be re-used, to store a pointer to the parent area. This will avoid more expensive searches, later on. Signed-off-by: Igor Stoppa Reviewed-by: Matthew Wilcox --- include/linux/mm_types.h | 1 + mm/vmalloc.c | 2 ++ 2 files changed, 3 insertions(+) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index fd1af6b9591d..c3a4825e10c0 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -84,6 +84,7 @@ struct page { void *s_mem; /* slab first object */ atomic_t compound_mapcount; /* first tail page */ /* page_deferred_list().next -- second tail page */ + struct vm_struct *area; }; /* Second double word */ diff --git a/mm/vmalloc.c b/mm/vmalloc.c index ebff729cc956..61a1ca22b0f6 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1536,6 +1536,7 @@ static void __vunmap(const void *addr, int deallocate_pages) struct page *page = area->pages[i]; BUG_ON(!page); + page->area = NULL; __free_pages(page, 0); } @@ -1705,6 +1706,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, area->nr_pages = i; goto fail; } + page->area = area; area->pages[i] = page; if (gfpflags_allow_blocking(gfp_mask|highmem_mask)) cond_resched();