From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757164AbeDZXny (ORCPT ); Thu, 26 Apr 2018 19:43:54 -0400 Received: from mail-yw0-f194.google.com ([209.85.161.194]:36519 "EHLO mail-yw0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757074AbeDZXnw (ORCPT ); Thu, 26 Apr 2018 19:43:52 -0400 X-Google-Smtp-Source: AB8JxZoPM6Ts+12ZiL8fRmfSdx1DL+MbW1n0j6JluIYTx9wvJ2V3nA8X5LTb7pZ8vkmB7VEJYqDPyg== From: Igor Stoppa X-Google-Original-From: Igor Stoppa To: willy@infradead.org, mhocko@kernel.org, akpm@linux-foundation.org, linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, igor.stoppa@huawei.com Subject: [PATCH 1/2] struct page: add field for vm_struct Date: Fri, 27 Apr 2018 03:42:42 +0400 Message-Id: <20180426234243.22267-2-igor.stoppa@huawei.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20180426234243.22267-1-igor.stoppa@huawei.com> References: <20180426234243.22267-1-igor.stoppa@huawei.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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: Jay Freyensee 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 21612347d311..c74e2aa9a48b 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -86,6 +86,7 @@ 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(); -- 2.14.1