From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id m8PMVJ32013040 for ; Thu, 25 Sep 2008 18:31:19 -0400 From: David Howells Subject: A question about alloc_pages() Date: Thu, 25 Sep 2008 23:31:16 +0100 Message-ID: <15178.1222381876@redhat.com> Sender: owner-linux-mm@kvack.org Return-Path: To: linux-mm@kvack.org Cc: dhowells@redhat.com List-ID: Hi, When alloc_pages() is asked to allocate a block of pages (order > 0), should I be able to expect that page_count(pages[0]) will be 1, and page_count() for all the other pages will be 0? As far as I can see, nothing in the allocator alters what's in the page count for pages beyond the first when pages are freed, and checks are made that these are 0 upon freeing, so it looks to me like this ought to be the case. However, I have a report that sometimes this isn't true, and I'm wondering if the allocator can't be relied on in this way, or whether there's a bug somewhere keeping a reference to a released page. David -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org