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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 798F3C4320D for ; Tue, 24 Sep 2019 20:51:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4B5EC21655 for ; Tue, 24 Sep 2019 20:51:48 +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="C9iEGEnK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2633304AbfIXUvo (ORCPT ); Tue, 24 Sep 2019 16:51:44 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:43866 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731288AbfIXUvn (ORCPT ); Tue, 24 Sep 2019 16:51:43 -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=+v9rUtMVLbceJYUrls0UAlCyrXq767IWhnxlCJpL7sY=; b=C9iEGEnKl6h5EiBPyWUTj+JpT uLY3285XCKnxDiiV+/TdezXJUYrO9Z1d+M85J5PS7/QEWylR1Kz74VJC86ovh8PtG6TJnDQwBooov M4CQSwewUvpMt4tp4Ilp0NZTttuXajXOGqQpZfcDqKQUBa8yl/7sWmifirAVWTNhx+BFmupzRJRMK IfiUoBQzq6eEdi1XU9TYkqWcr/t/DQ+CSiMGyty28VzbgVOSU4R1i5zl+QAtQJXJkTo/OxT1hFydF 77PmcrS+yO2XyCYZZ+rhk9F9aIvS276E+PGmW60r4uMYUpFfCQZKiZZt7+hkwc8DGt7Ul4cInMm/q tcB4/BSyA==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.2 #3 (Red Hat Linux)) id 1iCrmX-0005ZA-S8; Tue, 24 Sep 2019 20:51:33 +0000 Date: Tue, 24 Sep 2019 13:51:33 -0700 From: Matthew Wilcox To: cl@linux.com Cc: "Darrick J. Wong" , dsterba@suse.cz, Vlastimil Babka , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Pekka Enberg , David Rientjes , Ming Lei , Dave Chinner , Christoph Hellwig , linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, James Bottomley , linux-btrfs@vger.kernel.org, Roman Gushchin , Johannes Weiner Subject: Re: [PATCH v2 2/2] mm, sl[aou]b: guarantee natural alignment for kmalloc(power-of-two) Message-ID: <20190924205133.GK1855@bombadil.infradead.org> References: <20190826111627.7505-1-vbabka@suse.cz> <20190826111627.7505-3-vbabka@suse.cz> <20190923171710.GN2751@twin.jikos.cz> <20190923175146.GT2229799@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Tue, Sep 24, 2019 at 08:47:52PM +0000, cl@linux.com wrote: > On Mon, 23 Sep 2019, Darrick J. Wong wrote: > > > On Mon, Sep 23, 2019 at 07:17:10PM +0200, David Sterba wrote: > > > On Mon, Sep 23, 2019 at 06:36:32PM +0200, Vlastimil Babka wrote: > > > > So if anyone thinks this is a good idea, please express it (preferably > > > > in a formal way such as Acked-by), otherwise it seems the patch will be > > > > dropped (due to a private NACK, apparently). > > > > Oh, I didn't realize ^^^^^^^^^^^^ that *some* of us are allowed the > > privilege of gutting a patch via private NAK without any of that open > > development discussion incovenience. > > There was a public discussion about this issue and from what I can tell > the outcome was that the allocator already provides what you want. Which > was a mechanism to misalign objects and detect these issues. This > mechanism has been in use for over a decade. You missed the important part, which was *ENABLED BY DEFAULT*. People who are enabling a debugging option to debug their issues, should not have to first debug all the other issues that enabling that debugging option uncovers!