From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BA9EBC282DD for ; Thu, 23 May 2019 16:35:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8DDA520879 for ; Thu, 23 May 2019 16:35:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="NfRr1sg+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731116AbfEWQfz (ORCPT ); Thu, 23 May 2019 12:35:55 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:57060 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730752AbfEWQfz (ORCPT ); Thu, 23 May 2019 12:35:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=pTqw8vVT02TTedKtNx5d/snM21V25zXZwTaJRpzHF2s=; b=NfRr1sg+JCx7yTC0Y1pf6Ia/1 Jj1Q2JKIqRmnEF8uOXpqDpnr9jnvpqyQBNSvVaYyiHaVfePwCfQ0tbLKI4O2cMdcBLvDzvrte+2cX 1Ly+5JK/e9hbhNJbBJND96QDqY8TGO8OwTWGUrJF1N3V3YCU6jDgEx7HfhN+62O+StZI9eZfbaiEK mOxv1UxoWRRwqCOo3fLHC/klxOsWZN6BIyCzN2XJsws5lMcg06NHOBzxQvEFf9idGdYnR3B3EO+AW M523UGnpBClzSFsxc9+IrD/MOXokNRCGk9ezwriiL9ixjGlj/s3dDot/vgK2nXpf5NgXjUxy43LCg HgQHp8E6Q==; Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1hTqh3-0004Ox-JP; Thu, 23 May 2019 16:35:49 +0000 Date: Thu, 23 May 2019 09:35:49 -0700 From: Christoph Hellwig To: Oliver Neukum Cc: Christoph Hellwig , Jaewon Kim , linux-mm@kvack.org, gregkh@linuxfoundation.org, Jaewon Kim , m.szyprowski@samsung.com, ytk.lee@samsung.com, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Subject: Re: [RFC PATCH] usb: host: xhci: allow __GFP_FS in dma allocation Message-ID: <20190523163549.GA8692@infradead.org> References: <20190520055657.GA31866@infradead.org> <1558614729.3994.5.camel@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1558614729.3994.5.camel@suse.com> User-Agent: Mutt/1.9.2 (2017-12-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Thu, May 23, 2019 at 02:32:09PM +0200, Oliver Neukum wrote: > > Please switch to use memalloc_noio_save() instead. > > Thinking about this again, we have a problem. We introduced > memalloc_noio_save() in 3.10 . Hence the code should have been > correct in v4.14. Which means that either > 6518202970c1 "(mm/cma: remove unsupported gfp_mask > parameter from cma_alloc()" > is buggy, or the original issue with a delay of 2 seconds > still exist. > > Do we need to do something? cma_alloc calls into alloc_contig_range to do the actual allocation, which then calls current_gfp_context() to pick up the adjustments from memalloc_noio_save and friends. So at least in current mainline we should be fine.