From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f43.google.com (mail-pa0-f43.google.com [209.85.220.43]) by kanga.kvack.org (Postfix) with ESMTP id 9ABD36B006C for ; Thu, 26 Feb 2015 03:31:19 -0500 (EST) Received: by paceu11 with SMTP id eu11so12251042pac.7 for ; Thu, 26 Feb 2015 00:31:19 -0800 (PST) Received: from userp1040.oracle.com (userp1040.oracle.com. [156.151.31.81]) by mx.google.com with ESMTPS id pl9si210201pdb.47.2015.02.26.00.31.17 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Thu, 26 Feb 2015 00:31:18 -0800 (PST) From: Sasha Levin Subject: [PATCH] cma: debug: document new debugfs interface Date: Thu, 26 Feb 2015 03:31:03 -0500 Message-Id: <1424939463-18119-1-git-send-email-sasha.levin@oracle.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: akpm@linux-foundation.org, iamjoonsoo.kim@lge.com, linux-mm@kvack.org, Sasha Levin Document the structure and files under the new debugfs interface. Signed-off-by: Sasha Levin --- Documentation/cma/debugfs.txt | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) create mode 100644 Documentation/cma/debugfs.txt diff --git a/Documentation/cma/debugfs.txt b/Documentation/cma/debugfs.txt new file mode 100644 index 0000000..6cef20a --- /dev/null +++ b/Documentation/cma/debugfs.txt @@ -0,0 +1,21 @@ +The CMA debugfs interface is useful to retrieve basic information out of the +different CMA areas and to test allocation/release in each of the areas. + +Each CMA zone represents a directory under /cma/, indexed by the +kernel's CMA index. So the first CMA zone would be: + + /cma/cma-0 + +The structure of the files created under that directory is as follows: + + - [RO] base_pfn: The base PFN (Page Frame Number) of the zone. + - [RO] count: Amount of memory in the CMA area. + - [RO] order_per_bit: Order of pages represented by one bit. + - [RO] bitmap: The bitmap of page states in the zone. + - [WO] alloc: Allocate N pages from that CMA area. For example: + + echo 5 > /cma/cma-2/alloc + +would try to allocate 5 pages from the cma-2 area. + + - [WO] free: Free N pages from that CMA area, similar to the above. -- 1.7.10.4 -- 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