From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bruno =?UTF-8?B?UHLDqW1vbnQ=?= Subject: Re: 2.6.39-rc4+: Kernel leaking memory during FS scanning, regression? Date: Mon, 25 Apr 2011 20:36:06 +0200 Message-ID: <20110425203606.4e78246c@neptune.home> References: <20110424202158.45578f31@neptune.home> <20110424235928.71af51e0@neptune.home> <20110425114429.266A.A69D9226@jp.fujitsu.com> <20110425111705.786ef0c5@neptune.home> <20110425180450.1ede0845@neptune.home> <20110425190032.7904c95d@neptune.home> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: Mike Frysinger , KOSAKI Motohiro , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, "Paul E. McKenney" , Pekka Enberg To: Linus Torvalds Return-path: In-Reply-To: Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org On Mon, 25 April 2011 Linus Torvalds wrote: > On Mon, Apr 25, 2011 at 10:00 AM, Bruno Pr=C3=A9mont wrote: > > > > I hope tiny-rcu is not that broken... as it would mean driving any > > PREEMPT_NONE or PREEMPT_VOLUNTARY system out of memory when compiling > > packages (and probably also just unpacking larger tarballs or running > > things like du). >=20 > I'm sure that TINYRCU can be fixed if it really is the problem. >=20 > So I just want to make sure that we know what the root cause of your > problem is. It's quite possible that it _is_ a real leak of filp or > something, but before possibly wasting time trying to figure that out, > let's see if your config is to blame. With changed config (PREEMPT=3Dy, TREE_PREEMPT_RCU=3Dy) I haven't reproduced yet. When I was reproducing with TINYRCU things went normally for some time until suddenly slabs stopped being freed. > > And with system doing nothing (except monitoring itself) memory usage > > goes increasing all the time until it starves (well it seems to keep > > ~20M free, pushing processes it can to swap). Config is just being > > make oldconfig from working 2.6.38 kernel (answering default for new > > options) >=20 > How sure are you that the system really is idle? Quite frankly, the > constant growing doesn't really look idle to me. Except the SIGSTOPed build there is not much left, collectd running in background (it polls /proc for process counts, fork rate, memory usage, ... opening, reading, closing the files -- scanning every 10 seconds), slabtop on one terminal. CPU activity was near-zero with 10%-20% spikes of system use every 10 minutes and io-wait when all cache had been pushed out. > > Attached graph matching numbers of previous mail. (dropping caches was = at > > 17:55, system idle since then) >=20 > Nothing at all going on in 'ps' during that time? And what does > slabinfo say at that point now that kmemleak isn't dominating > everything else? ps definitely does not show anything special, 30 or so userspace processes. Didn't check ls /proc/*/fd though. Will do at next occurrence. Going to test further with various PREEMPT and RCU selections. Will report back as I progress (but won't have much time tomorrow). Bruno -- 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