Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757387Ab1FASaq (ORCPT ); Wed, 1 Jun 2011 14:30:46 -0400 Received: from mail-vw0-f46.google.com ([209.85.212.46]:63547 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752132Ab1FASao (ORCPT ); Wed, 1 Jun 2011 14:30:44 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=wT4OgYhY7d7Nokw9Gl0WcIH1wHZdBxFhR1M7UhOaCGd05UI1uh9lqvdDYZVXwS1Uy1 ui4PD4dXEKkgMmyCpq/nVvixBmjuasJwu8/Po6EvUJ+qRY02mEA9LrwfwP5+07i0aUzg lqmI/F5ho5YDr0V6y+JM58xs1tct16hg6DRQA= MIME-Version: 1.0 In-Reply-To: References: <1306922672-9012-1-git-send-email-dbaryshkov@gmail.com> Date: Wed, 1 Jun 2011 22:30:43 +0400 Message-ID: Subject: Re: [PATCH] Make GFP_DMA allocations w/o ZONE_DMA emit a warning instead of failing From: Dmitry Eremin-Solenikov To: David Rientjes Cc: KOSAKI Motohiro , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Russell King - ARM Linux , Mel Gorman , KAMEZAWA Hiroyuki , Rik van Riel , Andrew Morton Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2244 Lines: 58 On 6/1/11, David Rientjes wrote: > On Wed, 1 Jun 2011, Dmitry Eremin-Solenikov wrote: > >> I've hit this with IrDA driver on PXA. Also I've seen the report regarding >> other ARM platform (ep-something). Thus I've included Russell in the cc. >> > > So you want to continue to allow the page allocator to return pages from > anywhere, even when GFP_DMA is specified, just as though it was lowmem? Yes and no. I'm asking for the grace period for the drivers authors to be able to fix their code. After a grace period of one or two majors this permission should be removed and your original patch should be effective. > Why don't you actually address the problem with the driver you're > complaining about with the patch below, which I already posted to you a > few days ago? > > If this arm driver is going to be using GFP_DMA unconditionally, it better > require CONFIG_ZONE_DMA for it to actually be meaningful until such time > as it can be removed if it's truly not needed or generalized to only > specific pieces of hardware. No. This only workarounds the bug. And also a possible hundred of other bugs in the PXA/etc. ARM drivers. Instead I'm asking for the way to visualize all such bugs. Do you want to also add such workarounds to some PATA CF driver used on PXA? To _any_ of the drivers allocating the GFP_DMA memory? Then CONFIG_ZONE_DMA would serve no purpose. We can as well to drop that symbol. Believe me. > --- > drivers/net/irda/Kconfig | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/drivers/net/irda/Kconfig b/drivers/net/irda/Kconfig > --- a/drivers/net/irda/Kconfig > +++ b/drivers/net/irda/Kconfig > @@ -374,6 +374,7 @@ config VIA_FIR > config PXA_FICP > tristate "Intel PXA2xx Internal FICP" > depends on ARCH_PXA && IRDA > + select ZONE_DMA > help > Say Y or M here if you want to build support for the PXA2xx > built-in IRDA interface which can support both SIR and FIR. > -- With best wishes Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/