From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: [PATCH 4/5] mm, notifier: Add a lockdep map for invalidate_range_start Date: Thu, 15 Aug 2019 09:10:14 +0200 Message-ID: <20190815071014.GC7444@phenom.ffwll.local> References: <20190814202027.18735-1-daniel.vetter@ffwll.ch> <20190814202027.18735-5-daniel.vetter@ffwll.ch> <20190815000959.GD11200@ziepe.ca> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mail-ed1-x544.google.com (mail-ed1-x544.google.com [IPv6:2a00:1450:4864:20::544]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1BE426E8B1 for ; Thu, 15 Aug 2019 07:10:19 +0000 (UTC) Received: by mail-ed1-x544.google.com with SMTP id h8so1333892edv.7 for ; Thu, 15 Aug 2019 00:10:19 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20190815000959.GD11200@ziepe.ca> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Jason Gunthorpe Cc: Michal Hocko , Greg Kroah-Hartman , Daniel Vetter , Intel Graphics Development , LKML , DRI Development , linux-mm@kvack.org, =?iso-8859-1?B?Suly9G1l?= Glisse , Mike Rapoport , David Rientjes , Daniel Vetter , Andrew Morton , Christian =?iso-8859-1?Q?K=F6nig?= List-Id: dri-devel@lists.freedesktop.org T24gV2VkLCBBdWcgMTQsIDIwMTkgYXQgMDk6MDk6NTlQTSAtMDMwMCwgSmFzb24gR3VudGhvcnBl IHdyb3RlOgo+IE9uIFdlZCwgQXVnIDE0LCAyMDE5IGF0IDEwOjIwOjI2UE0gKzAyMDAsIERhbmll bCBWZXR0ZXIgd3JvdGU6Cj4gPiBUaGlzIGlzIGEgc2ltaWxhciBpZGVhIHRvIHRoZSBmc19yZWNs YWltIGZha2UgbG9ja2RlcCBsb2NrLiBJdCdzCj4gPiBmYWlybHkgZWFzeSB0byBwcm92b2tlIGEg c3BlY2lmaWMgbm90aWZpZXIgdG8gYmUgcnVuIG9uIGEgc3BlY2lmaWMKPiA+IHJhbmdlOiBKdXN0 IHByZXAgaXQsIGFuZCB0aGVuIG11bm1hcCgpIGl0Lgo+ID4gCj4gPiBBIGJpdCBoYXJkZXIsIGJ1 dCBzdGlsbCBkb2FibGUsIGlzIHRvIHByb3Zva2UgdGhlIG1tdSBub3RpZmllcnMgZm9yCj4gPiBh bGwgdGhlIHZhcmlvdXMgY2FsbGNoYWlucyB0aGF0IG1pZ2h0IGxlYWQgdG8gdGhlbS4gQnV0IGJv dGggYXQgdGhlCj4gPiBzYW1lIHRpbWUgaXMgcmVhbGx5IGhhcmQgdG8gcmVsaWFibGUgaGl0LCBl c3BlY2lhbGx5IHdoZW4geW91IHdhbnQgdG8KPiA+IGV4ZXJjaXNlIHBhdGhzIGxpa2UgZGlyZWN0 IHJlY2xhaW0gb3IgY29tcGFjdGlvbiwgd2hlcmUgaXQncyBub3QKPiA+IGVhc3kgdG8gY29udHJv bCB3aGF0IGV4YWN0bHkgd2lsbCBiZSB1bm1hcHBlZC4KPiA+IAo+ID4gQnkgaW50cm9kdWNpbmcg YSBsb2NrZGVwIG1hcCB0byB0aWUgdGhlbSBhbGwgdG9nZXRoZXIgd2UgYWxsb3cgbG9ja2RlcAo+ ID4gdG8gc2VlIGEgbG90IG1vcmUgZGVwZW5kZW5jaWVzLCB3aXRob3V0IGhhdmluZyB0byBhY3R1 YWxseSBoaXQgdGhlbQo+ID4gaW4gYSBzaW5nbGUgY2hhbGxjaGFpbiB3aGlsZSB0ZXN0aW5nLgo+ ID4gCj4gPiBBc2lkZTogU2luY2UgSSB0eXBlZCB0aGlzIHRvIHRlc3QgaTkxNSBtbXUgbm90aWZp ZXJzIEkndmUgb25seSByb2xsZWQKPiA+IHRoaXMgb3V0IGZvciB0aGUgaW52YWxpYXRlX3Jhbmdl X3N0YXJ0IGNhbGxiYWNrLiBJZiB0aGVyZSdzCj4gPiBpbnRlcmVzdCwgd2Ugc2hvdWxkIHByb2Jh Ymx5IHJvbGwgdGhpcyBvdXQgdG8gYWxsIG9mIHRoZW0uIEJ1dCBteQo+ID4gdW5kZXN0YW5kaW5n IG9mIGNvcmUgbW0gaXMgc2VyaW91c2x5IGxhY2tpbmcsIGFuZCBJJ20gbm90IGNsZWFyIG9uCj4g PiB3aGV0aGVyIHdlIG5lZWQgYSBsb2NrZGVwIG1hcCBmb3IgZWFjaCBjYWxsYmFjaywgb3Igd2hl dGhlciBzb21lIGNhbgo+ID4gYmUgc2hhcmVkLgo+IAo+IEkgd2FzIHRoaW5raW5nIGFib3V0IGRv aW5nIHNvbWV0aGluZyBsaWtlIHRoaXMuLgo+IAo+IElNSE8gb25seSByYW5nZV9lbmQgbmVlZHMg YW5ub3RhdGlvbiwgdGhlIG90aGVyIG9wcyBhcmUgZWl0aGVyIGFscmVhZHkKPiBub24tc2xlZXBp bmcgb3Igb25seSB1c2VkIGJ5IEtWTS4KClRoaXMgaXNudCcgYWJvdXQgc2xlZXBpbmcsIHRoaXMg aXMgYWJvdXQgbG9ja2luZyBsb29wcy4gQW5kIHRoZSBiaWdnZXN0CnJpc2sgZm9yIHRoYXQgaXMg ZnJvbSBkcml2ZXIgY29kZSwgYW5kIGF0IGxlYXN0IGhtbV9taXJyb3Igb25seSBoYXMgdGhlCmRy aXZlciBjb2RlIGNhbGxiYWNrIG9uIGludmFsaWRhdGVfcmFuZ2Vfc3RhcnQuIE9uY2UgdGhpbmcg SSBkaXNjb3ZlcmVkCnVzaW5nIHRoaXMgKGFuZCBpdCB3b3VsZCBiZSByZWFsbHkgaGFyZCB0byBz cG90LCBpdCdzIGRlZXBseSBuZWVzdGVkKSBpcwp0aGF0IGk5MTUgdXNlcnB0ci4KCkV2ZW4gaWYg aTkxNSB1c2VycHRyIHdvdWxkIHVzZSBobW1fbWlycm9yICh0byBmaXggdGhlIGlzc3VlIHlvdSBt ZW50aW9uCmJlbG93KSwgaWYgd2UgdGhlbiBzd2l0Y2ggdGhlIGFubm90YXRpb24gdG8gaW52YWxp ZGF0ZV9yYW5nZV9lbmQgbm90aGluZwppbnRlcmVzdGluZyB3b3VsZCBldmVyIGNvbWUgZnJvbSB0 aGlzLiBXZWxsLCB0aGUgb25seSB0aGluZyBpdCdkIGNhdGNoIGlzCmlzc3VlcyBpbiBobW1fbWly cm9yLCBidXQgSSB0aGluayBjb3JlIG1tIHJldmlldyB3aWxsIGNhdGNoIHRoYXQgYmVmb3JlIGl0 CnJlYWNoZXMgdXMgOi0pCgo+IEJUVywgSSBoYXZlIGZvdW5kIGl0IHN0cmFuZ2UgdGhhdCBpOTE1 IG9ubHkgdXNlcwo+IGludmFsaWRhdGVfcmFuZ2Vfc3RhcnQuIE5vdCByZWFsbHkgc3VyZSBob3cg aXQgaXMgYWJsZSB0byBkbwo+IHRoYXQuIFdvdWxkIGxvdmUgdG8ga25vdyB0aGUgYW5zd2VyIDop CgpJIHN1c3BlY3QgaXQncyBicm9rZW4gOi0vIE91ciB1c2VycHRyIGlzIC4uLiBub3QgdGhlIGJl c3QuIFBhcnQgb2YgdGhlCm1vdGl2YXRpb24gaGVyZS4KCj4gPiBSZXZpZXdlZC1ieTogSsOpcsO0 bWUgR2xpc3NlIDxqZ2xpc3NlQHJlZGhhdC5jb20+Cj4gPiBTaWduZWQtb2ZmLWJ5OiBEYW5pZWwg VmV0dGVyIDxkYW5pZWwudmV0dGVyQGludGVsLmNvbT4KPiA+ICBpbmNsdWRlL2xpbnV4L21tdV9u b3RpZmllci5oIHwgNiArKysrKysKPiA+ICBtbS9tbXVfbm90aWZpZXIuYyAgICAgICAgICAgIHwg NyArKysrKysrCj4gPiAgMiBmaWxlcyBjaGFuZ2VkLCAxMyBpbnNlcnRpb25zKCspCj4gPiAKPiA+ IGRpZmYgLS1naXQgYS9pbmNsdWRlL2xpbnV4L21tdV9ub3RpZmllci5oIGIvaW5jbHVkZS9saW51 eC9tbXVfbm90aWZpZXIuaAo+ID4gaW5kZXggYjZjMDA0YmQ5ZjZhLi45ZGQzOGMzMmZjNTMgMTAw NjQ0Cj4gPiArKysgYi9pbmNsdWRlL2xpbnV4L21tdV9ub3RpZmllci5oCj4gPiBAQCAtNDIsNiAr NDIsMTAgQEAgZW51bSBtbXVfbm90aWZpZXJfZXZlbnQgewo+ID4gIAo+ID4gICNpZmRlZiBDT05G SUdfTU1VX05PVElGSUVSCj4gPiAgCj4gPiArI2lmZGVmIENPTkZJR19MT0NLREVQCj4gPiArZXh0 ZXJuIHN0cnVjdCBsb2NrZGVwX21hcCBfX21tdV9ub3RpZmllcl9pbnZhbGlkYXRlX3JhbmdlX3N0 YXJ0X21hcDsKPiA+ICsjZW5kaWYKPiAKPiBJIHdvbmRlciB3aGF0IHRoZSB0cmFkZSBvZmYgaXMg aGF2aW5nIGEgZ2xvYmFsIG1hcCB2cyBhIG1hcCBpbiBlYWNoCj4gbW11X25vdGlmaWVyX21tID8K Ckxlc3MgcmVwb3J0cywgc3BlY2lmaWNhbGx5IG5vIHJlcG9ydHMgaW52b2x2aW5nIG11bHRpcGxl IGRpZmZlcmVudCBtbXUKbm90aWZpZXJzIHRvIGJ1aWxkIHRoZSBlbnRpcmUgY2hhaW4uIEJ1dCBJ J20gYXNzdW1pbmcgaXQncyBwb3NzaWJsZSB0bwpjb21iaW5lIHRoZW0gaW4gb25lIG1tIChrdm0r Z3B1K2luZmluaWJhbmQgaW4gb25lIHByb2Nlc3Mgc291bmRzIGxpa2UKc29tZXRoaW5nIHNvbWVv bmUgY291bGQgcmVhc29uYWJseSBkbyksIGFuZCBpdCB3aWxsIGhlbHAgdG8gbWFrZSBzdXJlCmV2 ZXJ5b25lIGZvbGxvd3MgdGhlIHNhbWUgcnVsZXMuCj4gCj4gPiAgLyoKPiA+ICAgKiBUaGUgbW11 IG5vdGlmaWVyX21tIHN0cnVjdHVyZSBpcyBhbGxvY2F0ZWQgYW5kIGluc3RhbGxlZCBpbgo+ID4g ICAqIG1tLT5tbXVfbm90aWZpZXJfbW0gaW5zaWRlIHRoZSBtbV90YWtlX2FsbF9sb2NrcygpIHBy b3RlY3RlZAo+ID4gQEAgLTMxMCwxMCArMzE0LDEyIEBAIHN0YXRpYyBpbmxpbmUgdm9pZCBtbXVf bm90aWZpZXJfY2hhbmdlX3B0ZShzdHJ1Y3QgbW1fc3RydWN0ICptbSwKPiA+ICBzdGF0aWMgaW5s aW5lIHZvaWQKPiA+ICBtbXVfbm90aWZpZXJfaW52YWxpZGF0ZV9yYW5nZV9zdGFydChzdHJ1Y3Qg bW11X25vdGlmaWVyX3JhbmdlICpyYW5nZSkKPiA+ICB7Cj4gPiArCWxvY2tfbWFwX2FjcXVpcmUo Jl9fbW11X25vdGlmaWVyX2ludmFsaWRhdGVfcmFuZ2Vfc3RhcnRfbWFwKTsKPiA+ICAJaWYgKG1t X2hhc19ub3RpZmllcnMocmFuZ2UtPm1tKSkgewo+ID4gIAkJcmFuZ2UtPmZsYWdzIHw9IE1NVV9O T1RJRklFUl9SQU5HRV9CTE9DS0FCTEU7Cj4gPiAgCQlfX21tdV9ub3RpZmllcl9pbnZhbGlkYXRl X3JhbmdlX3N0YXJ0KHJhbmdlKTsKPiA+ICAJfQo+ID4gKwlsb2NrX21hcF9yZWxlYXNlKCZfX21t dV9ub3RpZmllcl9pbnZhbGlkYXRlX3JhbmdlX3N0YXJ0X21hcCk7Cj4gPiAgfQo+IAo+IEFsc28g cmFuZ2VfZW5kIHNob3VsZCBoYXZlIHRoaXMgdG9vIC0gaXQgaGFzIGFsbCB0aGUgc2FtZQo+IGNv bnN0cmFpbnRzLiBJIHRoaW5rIGl0IGNhbiBzaGFyZSB0aGUgbWFwLiBTbyAncmFuZ2Vfc3RhcnRf bWFwJyBpcwo+IHByb2JhYmx5IG5vdCB0aGUgcmlnaHQgbmFtZS4KPiAKPiBJdCBtYXkgYWxzbyBt YWtlIHNvbWUgc2Vuc2UgdG8gZG8gYSBkdW1teSBhY3F1aXJlL3JlbGVhc2UgdW5kZXIgdGhlCj4g bW1fdGFrZV9hbGxfbG9ja3MoKSB0byBmb3JjaWJseSBpbmNyZWFzZSBtYXAgY292ZXJhZ2UgYW5k IHJlZHVjZSB0aGUKPiBzY2VuYXJpbyBjb21wbGV4aXR5IHJlcXVpcmVkIHRvIGhpdCBidWdzLgo+ IAo+IEFuZCBpZiB3ZSBkbyBkZWNpZGUgb24gdGhlIHJlY2xhaW0gdGhpbmcgaW4gbXkgb3RoZXIg ZW1haWwgdGhlbiB0aGUKPiByZWNsYWltIGRlcGVuZGVuY3kgY2FuIGJlIHJlbGlhYmx5IGluamVj dGVkIGJ5IGRvaW5nOgo+IAo+ICBmc19yZWNsYWltX2FjcXVpcmUoKTsKPiAgbG9ja19tYXBfYWNx dWlyZSgmX19tbXVfbm90aWZpZXJfaW52YWxpZGF0ZV9yYW5nZV9zdGFydF9tYXApOwo+ICBsb2Nr X21hcF9yZWxlYXNlKCZfX21tdV9ub3RpZmllcl9pbnZhbGlkYXRlX3JhbmdlX3N0YXJ0X21hcCk7 Cj4gIGZzX3JlY2xhaW1fcmVsZWFzZSgpOwo+IAo+IElmIEkgdW5kZXJzdGFuZCBsb2NrZGVwIHBy b3Blcmx5Li4KCkltZSBmc19yZWNsYWltIGluamVjdHMgdGhlIG1tdV9ub3RpZmllciBtYXAgaGVy ZSByZWxpYWJseSBhcyBzb29uIGFzCnlvdSd2ZSB0aHJvd24gb3V0IHRoZSBmaXJzdCBwYWdlY2Fj aGUgbW1hcCBvbiBhbnkgcHJvY2Vzcy4gVGhhdCAibWFrZSBzdXJlCndlIGluamVjdCBpdCBxdWlj a2x5IiBpcyB3aHkgdGhlIGxvY2tkZXAgaXMgX291dHNpZGVfIG9mIHRoZQptbV9oYXNfbm90aWZp ZXJzKCkgY2hlY2suIFNvIG5vIGZ1cnRoZXIgaW5qZWN0aW9uIG5lZWRlZCBpbW8uCi1EYW5pZWwK LS0gCkRhbmllbCBWZXR0ZXIKU29mdHdhcmUgRW5naW5lZXIsIEludGVsIENvcnBvcmF0aW9uCmh0 dHA6Ly9ibG9nLmZmd2xsLmNoCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fCmRyaS1kZXZlbCBtYWlsaW5nIGxpc3QKZHJpLWRldmVsQGxpc3RzLmZyZWVkZXNr dG9wLm9yZwpodHRwczovL2xpc3RzLmZyZWVkZXNrdG9wLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2Ry aS1kZXZlbA== 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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 6AE00C433FF for ; Thu, 15 Aug 2019 07:10:21 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DC45D20656 for ; Thu, 15 Aug 2019 07:10:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="ChRXyIAY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DC45D20656 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ffwll.ch Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 61BBC6B0003; Thu, 15 Aug 2019 03:10:20 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5CC3B6B0005; Thu, 15 Aug 2019 03:10:20 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4BB5F6B0007; Thu, 15 Aug 2019 03:10:20 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0087.hostedemail.com [216.40.44.87]) by kanga.kvack.org (Postfix) with ESMTP id 2A6A46B0003 for ; Thu, 15 Aug 2019 03:10:20 -0400 (EDT) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id BC2D38248AA7 for ; Thu, 15 Aug 2019 07:10:19 +0000 (UTC) X-FDA: 75823788558.19.crate46_2c536b93093a X-HE-Tag: crate46_2c536b93093a X-Filterd-Recvd-Size: 9394 Received: from mail-ed1-f68.google.com (mail-ed1-f68.google.com [209.85.208.68]) by imf31.hostedemail.com (Postfix) with ESMTP for ; Thu, 15 Aug 2019 07:10:18 +0000 (UTC) Received: by mail-ed1-f68.google.com with SMTP id z51so1301659edz.13 for ; Thu, 15 Aug 2019 00:10:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=sender:date:from:to:cc:subject:message-id:mail-followup-to :references:mime-version:content-disposition :content-transfer-encoding:in-reply-to:user-agent; bh=MDJNuF+hut+3YRzITm+axnt/d3tCzk1EPMOdFx9+DEE=; b=ChRXyIAYC7Rv8Y/vZMRO+O0Vlh5DAbIO5arU41q9pJ83DPuxW7q/ClkJgPqFUTZdkI RFRAoqFle60uB8sY67kiMD84/VinSId3gTA/SLZHu2D0j6h0ZI94eO3b9q/2tAqdpX+c FhwIh8fhcacKOZx661IGz8Odmwog/6hD0LIYg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :mail-followup-to:references:mime-version:content-disposition :content-transfer-encoding:in-reply-to:user-agent; bh=MDJNuF+hut+3YRzITm+axnt/d3tCzk1EPMOdFx9+DEE=; b=sUgSoaNf8IsxLm3/k48FkNYmswNBJanJWEXYfWek5SWq6MU+CXVgu0fHStpTWFearM jTj/YQFkMGdNCtdoXfXlg5JheahR+oabWwFIySMPRAry1cdacT1IPuOum5tg6yAFZKFl xP5yjsZgClg3pruA/oeFWz2gyQkXF5Q8qMnhEjuZCRkslnPVPx208rQu+20f63Nm/dPB sUA69XyCfa63wvtfmW0srsbgYNgIXF4bQgf7GxXGCrboKGEilCYNlzWKQ8NY9zmRuKvd oCvmDtraXZgSkwZTc0oHYOXqavgTeskP8VP4A+Yz8EWT8V7mjb7jphnUvWZpWUnY+aTt SCWw== X-Gm-Message-State: APjAAAUHL5982oTunFDOqPzRWI/LEp79JUpdyWbI0x8oh6nsLkxw0daz 2YrslOSOYwWfmqdC+KRR1sljggg8Ut9wFQ== X-Google-Smtp-Source: APXvYqzeqsYGya7a5gyG8JjAs2HpNqhI6YY0zlDjUM0vg0ax5p423oBpWZJFMYcam0b+ez79KuLR5w== X-Received: by 2002:a50:c101:: with SMTP id l1mr854278edf.157.1565853017629; Thu, 15 Aug 2019 00:10:17 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:569e:0:3106:d637:d723:e855]) by smtp.gmail.com with ESMTPSA id q21sm257841ejo.76.2019.08.15.00.10.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 15 Aug 2019 00:10:16 -0700 (PDT) Date: Thu, 15 Aug 2019 09:10:14 +0200 From: Daniel Vetter To: Jason Gunthorpe Cc: Daniel Vetter , LKML , linux-mm@kvack.org, DRI Development , Intel Graphics Development , Chris Wilson , Andrew Morton , David Rientjes , =?iso-8859-1?B?Suly9G1l?= Glisse , Michal Hocko , Christian =?iso-8859-1?Q?K=F6nig?= , Greg Kroah-Hartman , Mike Rapoport , Daniel Vetter Subject: Re: [PATCH 4/5] mm, notifier: Add a lockdep map for invalidate_range_start Message-ID: <20190815071014.GC7444@phenom.ffwll.local> Mail-Followup-To: Jason Gunthorpe , LKML , linux-mm@kvack.org, DRI Development , Intel Graphics Development , Chris Wilson , Andrew Morton , David Rientjes , =?iso-8859-1?B?Suly9G1l?= Glisse , Michal Hocko , Christian =?iso-8859-1?Q?K=F6nig?= , Greg Kroah-Hartman , Mike Rapoport , Daniel Vetter References: <20190814202027.18735-1-daniel.vetter@ffwll.ch> <20190814202027.18735-5-daniel.vetter@ffwll.ch> <20190815000959.GD11200@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20190815000959.GD11200@ziepe.ca> X-Operating-System: Linux phenom 4.19.0-5-amd64 User-Agent: Mutt/1.10.1 (2018-07-13) Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Aug 14, 2019 at 09:09:59PM -0300, Jason Gunthorpe wrote: > On Wed, Aug 14, 2019 at 10:20:26PM +0200, Daniel Vetter wrote: > > This is a similar idea to the fs_reclaim fake lockdep lock. It's > > fairly easy to provoke a specific notifier to be run on a specific > > range: Just prep it, and then munmap() it. > >=20 > > A bit harder, but still doable, is to provoke the mmu notifiers for > > all the various callchains that might lead to them. But both at the > > same time is really hard to reliable hit, especially when you want to > > exercise paths like direct reclaim or compaction, where it's not > > easy to control what exactly will be unmapped. > >=20 > > By introducing a lockdep map to tie them all together we allow lockde= p > > to see a lot more dependencies, without having to actually hit them > > in a single challchain while testing. > >=20 > > Aside: Since I typed this to test i915 mmu notifiers I've only rolled > > this out for the invaliate_range_start callback. If there's > > interest, we should probably roll this out to all of them. But my > > undestanding of core mm is seriously lacking, and I'm not clear on > > whether we need a lockdep map for each callback, or whether some can > > be shared. >=20 > I was thinking about doing something like this.. >=20 > IMHO only range_end needs annotation, the other ops are either already > non-sleeping or only used by KVM. This isnt' about sleeping, this is about locking loops. And the biggest risk for that is from driver code, and at least hmm_mirror only has the driver code callback on invalidate_range_start. Once thing I discovered using this (and it would be really hard to spot, it's deeply neested) is that i915 userptr. Even if i915 userptr would use hmm_mirror (to fix the issue you mention below), if we then switch the annotation to invalidate_range_end nothing interesting would ever come from this. Well, the only thing it'd catch is issues in hmm_mirror, but I think core mm review will catch that before i= t reaches us :-) > BTW, I have found it strange that i915 only uses > invalidate_range_start. Not really sure how it is able to do > that. Would love to know the answer :) I suspect it's broken :-/ Our userptr is ... not the best. Part of the motivation here. > > Reviewed-by: J=E9r=F4me Glisse > > Signed-off-by: Daniel Vetter > > include/linux/mmu_notifier.h | 6 ++++++ > > mm/mmu_notifier.c | 7 +++++++ > > 2 files changed, 13 insertions(+) > >=20 > > diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifie= r.h > > index b6c004bd9f6a..9dd38c32fc53 100644 > > +++ b/include/linux/mmu_notifier.h > > @@ -42,6 +42,10 @@ enum mmu_notifier_event { > > =20 > > #ifdef CONFIG_MMU_NOTIFIER > > =20 > > +#ifdef CONFIG_LOCKDEP > > +extern struct lockdep_map __mmu_notifier_invalidate_range_start_map; > > +#endif >=20 > I wonder what the trade off is having a global map vs a map in each > mmu_notifier_mm ? Less reports, specifically no reports involving multiple different mmu notifiers to build the entire chain. But I'm assuming it's possible to combine them in one mm (kvm+gpu+infiniband in one process sounds like something someone could reasonably do), and it will help to make sure everyone follows the same rules. >=20 > > /* > > * The mmu notifier_mm structure is allocated and installed in > > * mm->mmu_notifier_mm inside the mm_take_all_locks() protected > > @@ -310,10 +314,12 @@ static inline void mmu_notifier_change_pte(stru= ct mm_struct *mm, > > static inline void > > mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range= ) > > { > > + lock_map_acquire(&__mmu_notifier_invalidate_range_start_map); > > if (mm_has_notifiers(range->mm)) { > > range->flags |=3D MMU_NOTIFIER_RANGE_BLOCKABLE; > > __mmu_notifier_invalidate_range_start(range); > > } > > + lock_map_release(&__mmu_notifier_invalidate_range_start_map); > > } >=20 > Also range_end should have this too - it has all the same > constraints. I think it can share the map. So 'range_start_map' is > probably not the right name. >=20 > It may also make some sense to do a dummy acquire/release under the > mm_take_all_locks() to forcibly increase map coverage and reduce the > scenario complexity required to hit bugs. >=20 > And if we do decide on the reclaim thing in my other email then the > reclaim dependency can be reliably injected by doing: >=20 > fs_reclaim_acquire(); > lock_map_acquire(&__mmu_notifier_invalidate_range_start_map); > lock_map_release(&__mmu_notifier_invalidate_range_start_map); > fs_reclaim_release(); >=20 > If I understand lockdep properly.. Ime fs_reclaim injects the mmu_notifier map here reliably as soon as you've thrown out the first pagecache mmap on any process. That "make sur= e we inject it quickly" is why the lockdep is _outside_ of the mm_has_notifiers() check. So no further injection needed imo. -Daniel --=20 Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch