From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yw0-f199.google.com (mail-yw0-f199.google.com [209.85.161.199]) by kanga.kvack.org (Postfix) with ESMTP id 7A9EB6B002A for ; Thu, 26 Apr 2018 19:43:53 -0400 (EDT) Received: by mail-yw0-f199.google.com with SMTP id d9-v6so38133ywd.15 for ; Thu, 26 Apr 2018 16:43:53 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id o83-v6sor5869ywd.284.2018.04.26.16.43.52 for (Google Transport Security); Thu, 26 Apr 2018 16:43:52 -0700 (PDT) From: Igor Stoppa 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> In-Reply-To: <20180426234243.22267-1-igor.stoppa@huawei.com> References: <20180426234243.22267-1-igor.stoppa@huawei.com> Sender: owner-linux-mm@kvack.org List-ID: 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 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