From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f48.google.com (mail-wg0-f48.google.com [74.125.82.48]) by kanga.kvack.org (Postfix) with ESMTP id 774196B0032 for ; Fri, 9 Jan 2015 19:41:46 -0500 (EST) Received: by mail-wg0-f48.google.com with SMTP id l2so10840680wgh.7 for ; Fri, 09 Jan 2015 16:41:45 -0800 (PST) Received: from jenni1.inet.fi (mta-out1.inet.fi. [62.71.2.195]) by mx.google.com with ESMTP id u9si22293898wja.95.2015.01.09.16.41.45 for ; Fri, 09 Jan 2015 16:41:45 -0800 (PST) Date: Sat, 10 Jan 2015 02:41:43 +0200 From: "Kirill A. Shutemov" Subject: Re: [PATCH] mm/page_alloc.c: drop dead destroy_compound_page() Message-ID: <20150110004143.GA32424@node.dhcp.inet.fi> References: <1420458382-161038-1-git-send-email-kirill.shutemov@linux.intel.com> <20150107134039.25d4edfad92b62f3eee8b570@linux-foundation.org> <20150108141004.AB3461A2@black.fi.intel.com> <20150109162419.b52796aee45d6747399d2ebb@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150109162419.b52796aee45d6747399d2ebb@linux-foundation.org> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: "Kirill A. Shutemov" , aarcange@redhat.com, linux-mm@kvack.org On Fri, Jan 09, 2015 at 04:24:19PM -0800, Andrew Morton wrote: > On Thu, 8 Jan 2015 16:10:04 +0200 (EET) "Kirill A. Shutemov" wrote: > > > Something like this? > > > > >From 5fd481c1c521112e9cea407f5a2644c9f93d0e14 Mon Sep 17 00:00:00 2001 > > From: "Kirill A. Shutemov" > > Date: Thu, 8 Jan 2015 15:59:23 +0200 > > Subject: [PATCH] mm: more checks on free_pages_prepare() for tail pages > > > > Apart form being dead, destroy_compound_page() did some potentially > > useful checks. Let's re-introduce them in free_pages_prepare(), where > > they can be acctually triggered. > > > > compound_order() assert is already in free_pages_prepare(). We have few > > checks for tail pages left. > > > > I'm thinking we avoid the overhead unless CONFIG_DEBUG_VM? That's why there's "if (!IS_ENABLED(CONFIG_DEBUG_VM))". Is it wrong in some way? I didn't check, but I assume compiler is smart enough to get rid of free_tail_pages_check() if CONFIG_DEBUG_VM is not defined. No? -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org