From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx156.postini.com [74.125.245.156]) by kanga.kvack.org (Postfix) with SMTP id C4E8A6B0008 for ; Wed, 23 Jan 2013 11:26:19 -0500 (EST) Date: Wed, 23 Jan 2013 17:25:15 +0100 From: Andrew Lunn Subject: Re: [PATCH v2] mm: dmapool: use provided gfp flags for all dma_alloc_coherent() calls Message-ID: <20130123162515.GK13482@lunn.ch> References: <20121119144826.f59667b2.akpm@linux-foundation.org> <201301171049.30415.arnd@arndb.de> <50F800EB.6040104@web.de> <201301172026.45514.arnd@arndb.de> <50FABBED.1020905@web.de> <20130119185907.GA20719@lunn.ch> <5100022D.9050106@web.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5100022D.9050106@web.de> Sender: owner-linux-mm@kvack.org List-ID: To: Soeren Moch Cc: Andrew Lunn , Arnd Bergmann , Jason Cooper , Greg KH , Thomas Petazzoni , KAMEZAWA Hiroyuki , linux-kernel@vger.kernel.org, Michal Hocko , linux-mm@kvack.org, Kyungmin Park , Mel Gorman , Andrew Morton , Marek Szyprowski , linaro-mm-sig@lists.linaro.org, linux-arm-kernel@lists.infradead.org, Sebastian Hesselbarth On Wed, Jan 23, 2013 at 04:30:53PM +0100, Soeren Moch wrote: > On 19.01.2013 19:59, Andrew Lunn wrote: > >>Please find attached a debug log generated with your patch. > >> > >>I used the sata disk and two em28xx dvb sticks, no other usb devices, > >>no ethernet cable connected, tuners on saa716x-based card not used. > >> > >>What I can see in the log: a lot of coherent mappings from sata_mv > >>and orion_ehci, a few from mv643xx_eth, no other coherent mappings. > >>All coherent mappings are page aligned, some of them (from orion_ehci) > >>are not really small (as claimed in __alloc_from_pool). > >> > >>I don't believe in a memory leak. When I restart vdr (the application > >>utilizing the dvb sticks) then there is enough dma memory available > >>again. > > > >Hi Soeren > > > >We should be able to rule out a leak. Mount debugfg and then: > > > >while [ /bin/true ] ; do cat /debug/dma-api/num_free_entries ; sleep 60 ; done > > > >while you are capturing. See if the number goes down. > > > > Andrew > > Now I built a kernel with debugfs enabled. > It is not clear to me what I can see from the > dma-api/num_free_entries output. After reboot (vdr running) I see > decreasing numbers (3453 3452 3445 3430...), min_free_entries is > lower (3390). Sometimes the output is constant for several minutes ( > 3396 3396 3396 3396 3396,...) We are interesting in the long term behavior. Does it gradually go down? Or is it stable? If it goes down over time, its clearly a leak somewhere. Andrew -- 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