From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id A55576B002C for ; Wed, 19 Oct 2011 15:35:35 -0400 (EDT) Date: Wed, 19 Oct 2011 12:35:30 -0700 From: Stephen Hemminger Subject: regression in /proc/self/numa_maps with huge pages Message-ID: <20111019123530.2e59b86c@nehalam.linuxnetplumber.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Stephen Wilson Cc: linux-mm@kvack.org, KOSAKI Motohiro , Hugh Dickins , David Rientjes , Lee Schermerhorn , Alexey Dobriyan , Andrew Morton We are working on an application that uses a library that uses both huge pages and parses numa_maps. This application is no longer able to identify the socket id correctly for huge pages because the that 'huge' is no longer part of /proc/self/numa_maps. Basically, application sets up huge page mmaps, then reads /proc/self/numa_maps and skips all entries without the string " huge ". Then it looks for address and socket info. Why was this information dropped? Looks like the desire to be generic overstepped the desire to remain compatible. This regression in kernel ABI was introduced by: commit 29ea2f6982f1edc4302729116f2246dd7b45471d Author: Stephen Wilson Date: Tue May 24 17:12:42 2011 -0700 mm: use walk_page_range() instead of custom page table walking code Converting show_numa_map() to use the generic routine decouples the function from mempolicy.c, allowing it to be moved out of the mm subsystem and into fs/proc. Also, include KSM pages in /proc/pid/numa_maps statistics. The pagewalk logic implemented by check_pte_range() failed to account for such pages as they were not applicable to the page migration case. Signed-off-by: Stephen Wilson Reviewed-by: KOSAKI Motohiro Cc: Hugh Dickins Cc: David Rientjes Cc: Lee Schermerhorn Cc: Alexey Dobriyan Cc: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org