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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 69BFEC32751 for ; Wed, 31 Jul 2019 23:01:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3D5B5208E4 for ; Wed, 31 Jul 2019 23:01:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="ZqOvaIKn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727373AbfGaXBD (ORCPT ); Wed, 31 Jul 2019 19:01:03 -0400 Received: from mail-qt1-f196.google.com ([209.85.160.196]:46976 "EHLO mail-qt1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726417AbfGaXBA (ORCPT ); Wed, 31 Jul 2019 19:01:00 -0400 Received: by mail-qt1-f196.google.com with SMTP id h21so68202050qtn.13 for ; Wed, 31 Jul 2019 16:00:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=his7K/u+JOrtxUOs2Ekh5bM+KWEwFmVBgmJqXbtUu9E=; b=ZqOvaIKn5gpXMKF0lFuPBJqJcfbMtb3MPGVVmN3aQsXXr9MSvDSwnBIoLdfs4Cduzu QRA8c1QAxNjNjf8z0l9WF9x2Kw8+F1laR/NQxc3pyjTGetdSmplJvdURFUqnq6fIi7Y5 JS4Uvm5qizwTDtKpRb8KoH2QzFqssZQiMkXG494iOUBy1xVC1xhi6b5WNlWd0gIvaub2 W1XaQLBaV1YKYGli71I0JUa9mD2l2THlCEAFuHc01L/n1KcqIaj1oCEo7xdECmJqx39w 8DGqiJA1GV5ZIbSfFrgl6Pwwxp6UZXG3UZ0N0Nuntbj6x+BE/tlQ9FyXqpoxRRJYgrFQ ADTw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=his7K/u+JOrtxUOs2Ekh5bM+KWEwFmVBgmJqXbtUu9E=; b=VYkNOGJFXKdM2lGO6zIVSc6CQ2bC5i7UnY9z4DKK86/YH+LecZk4lPA2fu1Lda0pEc DXHXDsKIVZ2T+YHY0gD+vj8zYv64yHhtClV0sLoRZ2bMLyVBjUsYNDGqV4nrEKFCg08r hXMHTAFvJ3JFL3Mm0C7lzrSvh0dbWflkVpnSwDDAZ5NJqNd2J2c67+ssixY0lj2vZOi9 e5oLO0nDMcm1X7cy4qecjIFW+mzMmUwFULg06vCZWFePElUUAnTpbopS2A/ecObmqxHO ePvqaIHPnaJeDVYbZbb/4PAJ4cPYrStavrsTF1Cl7KMEvOMmUQxXckm/U83MdJdSLDPM 9ykw== X-Gm-Message-State: APjAAAWZoqwB7NlsKdgFzSzyZL+LjMPRlU7AzQaPpYbZcVxj1tW1aMmH zGAy2IAUu/rJ/aywOz7Cs0dgdA== X-Google-Smtp-Source: APXvYqwJPf0PqUhqgGpVR2IzxGvlfGykM1M7nRsba5YS0Ne3y5wjASuoEvOh6D7uIAmXvcUuYYR1nQ== X-Received: by 2002:ac8:688:: with SMTP id f8mr11797584qth.130.1564614059446; Wed, 31 Jul 2019 16:00:59 -0700 (PDT) Received: from ziepe.ca (hlfxns017vw-156-34-55-100.dhcp-dynamic.fibreop.ns.bellaliant.net. [156.34.55.100]) by smtp.gmail.com with ESMTPSA id n18sm29218512qtr.28.2019.07.31.16.00.57 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 31 Jul 2019 16:00:58 -0700 (PDT) Received: from jgg by mlx.ziepe.ca with local (Exim 4.90_1) (envelope-from ) id 1hsxab-00009Y-B9; Wed, 31 Jul 2019 20:00:57 -0300 Date: Wed, 31 Jul 2019 20:00:57 -0300 From: Jason Gunthorpe To: Jason Wang Cc: "Michael S. Tsirkin" , syzbot , aarcange@redhat.com, akpm@linux-foundation.org, christian@brauner.io, davem@davemloft.net, ebiederm@xmission.com, elena.reshetova@intel.com, guro@fb.com, hch@infradead.org, james.bottomley@hansenpartnership.com, jglisse@redhat.com, keescook@chromium.org, ldv@altlinux.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-parisc@vger.kernel.org, luto@amacapital.net, mhocko@suse.com, mingo@kernel.org, namit@vmware.com, peterz@infradead.org, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk, wad@chromium.org Subject: Re: WARNING in __mmdrop Message-ID: <20190731230057.GA32346@ziepe.ca> References: <20190726094756-mutt-send-email-mst@kernel.org> <0792ee09-b4b7-673c-2251-e5e0ce0fbe32@redhat.com> <20190729045127-mutt-send-email-mst@kernel.org> <4d43c094-44ed-dbac-b863-48fc3d754378@redhat.com> <20190729104028-mutt-send-email-mst@kernel.org> <96b1d67c-3a8d-1224-e9f0-5f7725a3dc10@redhat.com> <20190730110633-mutt-send-email-mst@kernel.org> <421a1af6-df06-e4a6-b34f-526ac123bc4a@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <421a1af6-df06-e4a6-b34f-526ac123bc4a@redhat.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org On Wed, Jul 31, 2019 at 04:49:32PM +0800, Jason Wang wrote: > Yes, looking at the synchronization implemented by other MMU notifiers. > Vhost is even the simplest. I think that is only because it calls gup under a spinlock, which is, IMHO, not great. Jason 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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 A21E4C433FF for ; Wed, 31 Jul 2019 23:01:04 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 75D4D206A2 for ; Wed, 31 Jul 2019 23:01:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="CekfK/Ow"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="ZqOvaIKn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 75D4D206A2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=jEJYYM60c1TPe2EdZMsHqwWEUlaTDBOlIFr99lK8R6I=; b=CekfK/OwNjBoPW 4IuaTgam0TReSJOwSGBdU07EZnI7sSp6S0GGEiUISQyH7R49WoChtBKmQop062f9l0GoDOPnk3ii9 9M1qeA8xWwy1mJYmKecj4hJYFrwQ2ZJ3nw2vEchPEZNttuX1S3kV4/MvF5tQJvMgEBsh9DEE04+sj uzTfsa2wwFhI2IjBCt0ShjLwwQEFO6d/rcDeIQyII3G4wk5/JX2r8YcpH4Bif3Qzz0ZZk+Ww9Pn0W HYhzPNyE4QvxIudYrLnzll33HOW3BLDUoEd1ctL58B265KPkcedbvXZslft4BS40yZ4eG+KDo03ni M3G2vyzNHGXg+iyPumvQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hsxah-0003pW-LF; Wed, 31 Jul 2019 23:01:03 +0000 Received: from mail-qt1-x844.google.com ([2607:f8b0:4864:20::844]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hsxaf-0003oy-An for linux-arm-kernel@lists.infradead.org; Wed, 31 Jul 2019 23:01:02 +0000 Received: by mail-qt1-x844.google.com with SMTP id d23so68286881qto.2 for ; Wed, 31 Jul 2019 16:01:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=his7K/u+JOrtxUOs2Ekh5bM+KWEwFmVBgmJqXbtUu9E=; b=ZqOvaIKn5gpXMKF0lFuPBJqJcfbMtb3MPGVVmN3aQsXXr9MSvDSwnBIoLdfs4Cduzu QRA8c1QAxNjNjf8z0l9WF9x2Kw8+F1laR/NQxc3pyjTGetdSmplJvdURFUqnq6fIi7Y5 JS4Uvm5qizwTDtKpRb8KoH2QzFqssZQiMkXG494iOUBy1xVC1xhi6b5WNlWd0gIvaub2 W1XaQLBaV1YKYGli71I0JUa9mD2l2THlCEAFuHc01L/n1KcqIaj1oCEo7xdECmJqx39w 8DGqiJA1GV5ZIbSfFrgl6Pwwxp6UZXG3UZ0N0Nuntbj6x+BE/tlQ9FyXqpoxRRJYgrFQ ADTw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=his7K/u+JOrtxUOs2Ekh5bM+KWEwFmVBgmJqXbtUu9E=; b=jS3WZJSq0OSqupCverzekGvhP70i1SXKIvhd234qyMzz7kP7QGfOSylS08FSiW78MH 0OmoW6aNERnexaUJXfHXXyr2SMaPFjqpXEBJ2f8Vut9Ni3cKBMpJQwOVctmTDNz3fldn UeYybtX+YJma3GlB/E5Brdp3V+D0FotbQabl9Jla59EQp/pTkaEPafrll8Rl4/VFavx2 KgvIpjDbKyH1nDbyw9aN/5FJtKb4xcbAzbXNoshkOIkyKc7iSMdcqsObD6SOH5cMLcgy 29aEdEwEdu+X0KGlPnUeA469YRu52bWqSeCgeDw+UFS1QSv0nVYnV54go8yCDvbM6LTX EzyA== X-Gm-Message-State: APjAAAXWLJKfu/gMLuNuUEjSrVHadT+r5nJFhwR01amIAwYKFHgPQfhw NPdML71hz7sk2Ewes46xCKyeXg== X-Google-Smtp-Source: APXvYqwJPf0PqUhqgGpVR2IzxGvlfGykM1M7nRsba5YS0Ne3y5wjASuoEvOh6D7uIAmXvcUuYYR1nQ== X-Received: by 2002:ac8:688:: with SMTP id f8mr11797584qth.130.1564614059446; Wed, 31 Jul 2019 16:00:59 -0700 (PDT) Received: from ziepe.ca (hlfxns017vw-156-34-55-100.dhcp-dynamic.fibreop.ns.bellaliant.net. [156.34.55.100]) by smtp.gmail.com with ESMTPSA id n18sm29218512qtr.28.2019.07.31.16.00.57 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 31 Jul 2019 16:00:58 -0700 (PDT) Received: from jgg by mlx.ziepe.ca with local (Exim 4.90_1) (envelope-from ) id 1hsxab-00009Y-B9; Wed, 31 Jul 2019 20:00:57 -0300 Date: Wed, 31 Jul 2019 20:00:57 -0300 From: Jason Gunthorpe To: Jason Wang Subject: Re: WARNING in __mmdrop Message-ID: <20190731230057.GA32346@ziepe.ca> References: <20190726094756-mutt-send-email-mst@kernel.org> <0792ee09-b4b7-673c-2251-e5e0ce0fbe32@redhat.com> <20190729045127-mutt-send-email-mst@kernel.org> <4d43c094-44ed-dbac-b863-48fc3d754378@redhat.com> <20190729104028-mutt-send-email-mst@kernel.org> <96b1d67c-3a8d-1224-e9f0-5f7725a3dc10@redhat.com> <20190730110633-mutt-send-email-mst@kernel.org> <421a1af6-df06-e4a6-b34f-526ac123bc4a@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <421a1af6-df06-e4a6-b34f-526ac123bc4a@redhat.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190731_160101_515989_EBFA06A2 X-CRM114-Status: UNSURE ( 6.74 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mhocko@suse.com, "Michael S. Tsirkin" , peterz@infradead.org, ldv@altlinux.org, james.bottomley@hansenpartnership.com, linux-mm@kvack.org, namit@vmware.com, mingo@kernel.org, elena.reshetova@intel.com, keescook@chromium.org, aarcange@redhat.com, davem@davemloft.net, hch@infradead.org, christian@brauner.io, syzbot , syzkaller-bugs@googlegroups.com, jglisse@redhat.com, viro@zeniv.linux.org.uk, linux-arm-kernel@lists.infradead.org, wad@chromium.org, linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org, luto@amacapital.net, ebiederm@xmission.com, akpm@linux-foundation.org, guro@fb.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Jul 31, 2019 at 04:49:32PM +0800, Jason Wang wrote: > Yes, looking at the synchronization implemented by other MMU notifiers. > Vhost is even the simplest. I think that is only because it calls gup under a spinlock, which is, IMHO, not great. Jason _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel