From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by rv-out-0708.google.com with SMTP id f25so1120897rvb.26 for ; Mon, 08 Dec 2008 09:48:40 -0800 (PST) Message-ID: <2f11576a0812080948k135e15c5h2bc727355235f94@mail.gmail.com> Date: Tue, 9 Dec 2008 02:48:40 +0900 From: "KOSAKI Motohiro" Subject: Re: [PATCH] vmscan: skip freeing memory from zones with lots free In-Reply-To: <20081208220016.53FB.KOSAKI.MOTOHIRO@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20081129195357.813D.KOSAKI.MOTOHIRO@jp.fujitsu.com> <20081208205842.53F8.KOSAKI.MOTOHIRO@jp.fujitsu.com> <20081208220016.53FB.KOSAKI.MOTOHIRO@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton , Rik van Riel Cc: kosaki.motohiro@jp.fujitsu.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Peter Zijlstra , Johannes Weiner , Christoph Lameter , Nick Piggin List-ID: > example, > > Called zone_watermark_ok(zone, 2, pages_min, 0, 0); > pages_min = 64 > free pages = 80 > > case A. > > order nr_pages > -------------------- > 2 5 > 1 10 > 0 30 > > -> zone_watermark_ok() return 1 > > case B. > > order nr_pages > -------------------- > 3 10 > 2 0 > 1 0 > 0 0 > > -> zone_watermark_ok() return 0 Doh! this example is obiously buggy. I guess Mr. KOSAKI is very silly or Idiot. I recommend to he get feathery blanket and good sleeping, instead black black coffee ;-) ...but below mesurement result still true. > This patch change zone_watermark_ok() logic to prefer large contenious block. > > > Result: > > test machine: > CPU: ia64 x 8 > MEM: 8GB > > benchmark: > $ tbench 8 (three times mesurement) > > tbench works between about 600sec. > alloc_pages() and zone_watermark_ok() are called about 15,000,000 times. > > > 2.6.28-rc6 this patch > > throughput max-latency throughput max-latency > --------------------------------------------------------- > 1480.92 20.896 1,490.27 19.606 > 1483.94 19.202 1,482.86 21.082 > 1478.93 22.215 1,490.57 23.493 > > avg 1,481.26 20.771 1,487.90 21.394 > std 2.06 1.233 3.56 1.602 > min 1,478.93 19.202 1,477.86 19.606 > max 1,483.94 22.215 1,490.57 23.493 > > > throughput improve about 5MB/sec. it over measurement wobbly. -- 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