From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wu Fengguang Subject: [PATCH] writeback: remove the internal 5% low bound on dirty_ratio Date: Fri, 20 Aug 2010 11:25:06 +0800 Message-ID: <20100820032506.GA6662@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, riel@redhat.com, david@fromorbit.com, hch@lst.de, axboe@kernel.dk, Michael Rubin , Jan Kara , Neil Brown To: Andrew Morton Return-path: Received: from mga01.intel.com ([192.55.52.88]:41903 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751059Ab0HTDZK (ORCPT ); Thu, 19 Aug 2010 23:25:10 -0400 Content-Disposition: inline Sender: linux-fsdevel-owner@vger.kernel.org List-ID: The dirty_ratio was silently limited to >= 5%. This is not a user expected behavior. Let's rip it. It's not likely the user space will depend on the old behavior. So the risk of breaking user space is very low. CC: Jan Kara CC: Neil Brown Signed-off-by: Wu Fengguang --- mm/page-writeback.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) --- linux-next.orig/mm/page-writeback.c 2010-08-20 10:55:17.000000000 +0800 +++ linux-next/mm/page-writeback.c 2010-08-20 10:56:36.000000000 +0800 @@ -415,14 +415,8 @@ void global_dirty_limits(unsigned long * if (vm_dirty_bytes) dirty = DIV_ROUND_UP(vm_dirty_bytes, PAGE_SIZE); - else { - int dirty_ratio; - - dirty_ratio = vm_dirty_ratio; - if (dirty_ratio < 5) - dirty_ratio = 5; - dirty = (dirty_ratio * available_memory) / 100; - } + else + dirty = (vm_dirty_ratio * available_memory) / 100; if (dirty_background_bytes) background = DIV_ROUND_UP(dirty_background_bytes, PAGE_SIZE);