From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f169.google.com (mail-wi0-f169.google.com [209.85.212.169]) by kanga.kvack.org (Postfix) with ESMTP id 5DB966B0038 for ; Tue, 2 Dec 2014 19:42:50 -0500 (EST) Received: by mail-wi0-f169.google.com with SMTP id r20so31556359wiv.2 for ; Tue, 02 Dec 2014 16:42:49 -0800 (PST) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id jt3si38622271wid.19.2014.12.02.16.42.49 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 02 Dec 2014 16:42:49 -0800 (PST) From: Mel Gorman Subject: [PATCH 0/2] Improve documentation of FADV_DONTNEED behaviour Date: Wed, 3 Dec 2014 00:42:45 +0000 Message-Id: <1417567367-9298-1-git-send-email-mgorman@suse.de> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton , Michael Kerrisk Cc: Linux-MM , LKML , Mel Gorman Partial page discard requests are ignored and the documentation on why this is correct behaviour sucks. A readahead patch looked like a "regression" to a random IO storage benchmark because posix_fadvise() was used incorrectly to force IO requests to go to disk. In reality, the benchmark sucked but it was non-obvious why. Patch 1 updates the kernel comment in case someone "fixes" either readahead or fadvise for inappropriate reasons. Patch 2 updates the relevant man page on the rough off chance that application developers do not read kernel source comments. -- 2.1.2 -- 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