From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: Re: [PATCH] mm: kill kmemcheck Date: Thu, 12 Mar 2015 08:51:08 -0400 Message-ID: <55018BBC.6010903@oracle.com> References: <1426074547-21888-1-git-send-email-sasha.levin@oracle.com> <55013B38.6040100@iki.fi> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <55013B38.6040100@iki.fi> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppe-linuxppc-embedded-2=m.gmane.org@lists.ozlabs.org Sender: "Linuxppc-dev" To: Pekka Enberg , linux-kernel@vger.kernel.org Cc: Vladimir Davydov , Geert Uytterhoeven , SUPERH , Catalin Marinas , Will Deacon , Jianyu Zhan , Paul Mackerras , Pavel Machek , Miklos Szeredi , Christoph Lameter , Marek Szyprowski , "open list:GENERIC INCLUDE/A..." , Andi Kleen , Russell King , Jingoo Han , James Morris , Chris Bainbridge , Antti Palosaari , Mel Gorman , Ritesh Harjani , Shaohua Li , Alexander Duyck , Wang Nan , Jiri List-Id: linux-arch.vger.kernel.org T24gMDMvMTIvMjAxNSAwMzowNyBBTSwgUGVra2EgRW5iZXJnIHdyb3RlOgo+IEhpIFNhc2hhLAo+ IAo+IE9uIDMvMTEvMTUgMTo0MyBQTSwgU2FzaGEgTGV2aW4gd3JvdGU6Cj4+IEFzIGRpc2N1c3Nl ZCBvbiBMU0YvTU0sIGtpbGwga21lbWNoZWNrLgo+Pgo+PiBLQVNhbiBpcyBhIHJlcGxhY2VtZW50 IHRoYXQgaXMgYWJsZSB0byB3b3JrIHdpdGhvdXQgdGhlIGxpbWl0YXRpb24gb2YKPj4ga21lbWNo ZWNrIChzaW5nbGUgQ1BVLCBzbG93KS4gS0FTYW4gaXMgYWxyZWFkeSB1cHN0cmVhbS4KPj4KPj4g V2UgYXJlIGFsc28gbm90IGF3YXJlIG9mIGFueSB1c2VycyBvZiBrbWVtY2hlY2sgKG9yIHVzZXJz IHdobyBkb24ndCBjb25zaWRlcgo+PiBLQVNhbiBhcyBhIHN1aXRhYmxlIHJlcGxhY2VtZW50KS4K Pj4KPj4gSSd2ZSBidWlsZCB0ZXN0ZWQgaXQgdXNpbmcgYWxsW3llcyxubyxtb2RdY29uZmlnIGFu ZCBmdXp6ZWQgYSBiaXQgd2l0aCB0aGlzCj4+IHBhdGNoIGFwcGxpZWQsIGRpZG4ndCBub3RpY2Ug YW55IGJhZCBiZWhhdmlvdXIuCj4+Cj4+IFNpZ25lZC1vZmYtYnk6IFNhc2hhIExldmluIDxzYXNo YS5sZXZpbkBvcmFjbGUuY29tPgo+IAo+IENhbiB5b3UgZWxhYm9yYXRlIG9uIHdoYXQgZXhhY3Rs eSB3YXMgZGlzY3Vzc2VkIGF0IExTRi9NTT8gUHJlZmVyYWJseSBpbiB0aGUgY29tbWl0IGxvZy4g Oy0pCgpUaGVyZSB3YXNuJ3QgYSBsb25nIGRpc2N1c3Npb24gYWJvdXQgcmVtb3Zpbmcga21lbWNo ZWNrLCBpdCBqdXN0IGZvbGxvd2VkIHVwCmEgS0FTYW4gdG9waWMgYW5kIHRoZSBxdWVzdGlvbiBv ZiB3aGV0aGVyIGttZW1jaGVjayBjYW4gYmUgZGVwcmVjYXRlZCBub3cKdGhhdCBLQVNhbiBpcyBt ZXJnZWQgY2FtZSB1cC4KCk5vIG9uZSBhdCB0aGUgcm9vbSBkaWRuJ3QgdXNlIGl0LCBrbmV3IGEg dXNlciBvZiBpdCwgb3IgY291bGRuJ3QgZGVzY3JpYmUgYQp1c2VjYXNlIHdoZXJlIGttZW1jaGVj ayB3YXMgc3VwZXJpb3IgdG8gS0FTYW4gLSBzbyB0aGUgY29uY2x1c2lvbiB3YXMgdG8gdHJ5CmFu ZCByZXBsYWNlIGl0LgoKVGhlIG9ubHkgdGhpbmcgSSBjYW4gcmVhbGx5IHB1dCBpbiB0aGUgY2hh bmdlbG9nIGlzIGEgcmVmZXJlbmNlIHRvIHRoZSBLQVNhbgpkb2NzIGFuZCB0byBhc2sgZm9sa3Mg dG8gY29tcGxhaW4gbG91ZGx5IGlmIHdlIG1pc3NlZCBhIHVzZWNhc2UuCgoKVGhhbmtzLApTYXNo YQpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpMaW51eHBw Yy1kZXYgbWFpbGluZyBsaXN0CkxpbnV4cHBjLWRldkBsaXN0cy5vemxhYnMub3JnCmh0dHBzOi8v bGlzdHMub3psYWJzLm9yZy9saXN0aW5mby9saW51eHBwYy1kZXY= From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp1040.oracle.com (aserp1040.oracle.com [141.146.126.69]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 912F81A0745 for ; Thu, 12 Mar 2015 23:52:38 +1100 (AEDT) Message-ID: <55018BBC.6010903@oracle.com> Date: Thu, 12 Mar 2015 08:51:08 -0400 From: Sasha Levin MIME-Version: 1.0 To: Pekka Enberg , linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: kill kmemcheck References: <1426074547-21888-1-git-send-email-sasha.levin@oracle.com> <55013B38.6040100@iki.fi> In-Reply-To: <55013B38.6040100@iki.fi> Content-Type: text/plain; charset=windows-1252 Cc: Vladimir Davydov , Geert Uytterhoeven , SUPERH , Catalin Marinas , Will Deacon , Jianyu Zhan , Paul Mackerras , Pavel Machek , Miklos Szeredi , Christoph Lameter , Marek Szyprowski , "open list:GENERIC INCLUDE/A..." , Andi Kleen , Russell King , Jingoo Han , James Morris , Chris Bainbridge , Antti Palosaari , Mel Gorman , Ritesh Harjani , Shaohua Li , Alexander Duyck , Wang Nan , Jiri Pirko , Daniel J Blueman , Rusty Russell , Jens Axboe , Alexander Viro , Thomas Gleixner , Konstantin Khlebnikov , Willem de Bruijn , Greg Kroah-Hartman , Randy Dunlap , "Rafael J. Wysocki" , Rabin Vincent , "Aneesh Kumar K.V" , Jiri Kosina , Tejun Heo , Andrew Morton , Patrick McHardy , Christoffer Dall , Mark Rutland , DOCUMENTATION , Dave Hansen , Eric Dumazet , Jungseung Lee , Masami Hiramatsu , Stephen Rothwell , Qiaowei Ren , Prarit Bhargava , bob picco , Sungjinn Chung , Quentin Lambert , Hugh Dickins , Yasuaki Ishimatsu , Kukjin Kim , Pranith Kumar , Tom Herbert , CRYPTO API , Rik van Riel , Johannes Berg , Mauro Carvalho Chehab , Eyal Perry , Joe Perches , chishanmingshen , Cyrill Gorcunov , Boris Ostrovsky , Yinghai Lu , Steven Honeyman , ARM PORT , Theodore Ts'o , Pekka Enberg , David Vrabel , David Rientjes , Joonsoo Kim , Michal Hocko , Paul Gortmaker , Jan Beulich , "moderated list:OPENRISC ARCHITEC..." , Guan Xuetao , Sam Ravnborg , Jonathan Corbet , Andrey Ryabinin , Dexuan Cui , Vegard Nossum , Alexey Kuznetsov , "Paul E. McKenney" , Fenghua Yu , Kees Cook , Arnd Bergmann , Suresh Siddha , Josh Triplett , Steven Rostedt , Borislav Petkov , Andrey Konovalov , Scott Wood , Bryan O'Donoghue , Dan Streetman , Oleg Nesterov , Andy Lutomirski , Hannes Frederic Sowa , linux-fsdevel@vger.kernel.org, "David S. Miller" , "Kirill A. Shutemov" , "Michael S. Tsirkin" , Peter Zijlstra , MEMORY MANAGEMENT , Davidlohr Bueso , Paul Cassella , "H. Peter Anvin" , "open list:SPARC + UltraSPAR..." , Xishi Qiu , Alexei Starovoitov , Jonas Bonn , Herbert Xu , Richard Weinberger , "maintainer:X86 ARCHITECTURE..." , Ingo Molnar , Aaron Tomlin , Greg Thelen , "Eric W. Biederman" , Konrad Rzeszutek Wilk , Fabian Frederick , Michal Marek , Jungseok Lee , Dave Jones , Andy Shevchenko , Vlastimil Babka , Juergen Gross , Hideaki YOSHIFUJI , "open list:NETWORKING \[GENERAL\]" , Daniel Borkmann , Horia Geanta , Johannes Weiner , "open list:LINUX FOR POWERPC..." , Anton Blanchard List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 03/12/2015 03:07 AM, Pekka Enberg wrote: > Hi Sasha, > > On 3/11/15 1:43 PM, Sasha Levin wrote: >> As discussed on LSF/MM, kill kmemcheck. >> >> KASan is a replacement that is able to work without the limitation of >> kmemcheck (single CPU, slow). KASan is already upstream. >> >> We are also not aware of any users of kmemcheck (or users who don't consider >> KASan as a suitable replacement). >> >> I've build tested it using all[yes,no,mod]config and fuzzed a bit with this >> patch applied, didn't notice any bad behaviour. >> >> Signed-off-by: Sasha Levin > > Can you elaborate on what exactly was discussed at LSF/MM? Preferably in the commit log. ;-) There wasn't a long discussion about removing kmemcheck, it just followed up a KASan topic and the question of whether kmemcheck can be deprecated now that KASan is merged came up. No one at the room didn't use it, knew a user of it, or couldn't describe a usecase where kmemcheck was superior to KASan - so the conclusion was to try and replace it. The only thing I can really put in the changelog is a reference to the KASan docs and to ask folks to complain loudly if we missed a usecase. Thanks, Sasha