From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: [PATCH] build fix for generic debug pagealloc Date: Fri, 3 Apr 2009 18:44:50 +0200 Message-ID: <20090403164450.GC3047@elte.hu> References: <20090402163145.GA28728@localhost.localdomain> <20090402094522.b29004c8.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20090402094522.b29004c8.akpm@linux-foundation.org> Sender: linux-kernel-owner@vger.kernel.org To: Andrew Morton , "Rafael J. Wysocki" Cc: Akinobu Mita , Alexander Beregalov , "linux-next@vger.kernel.org" , LKML , linux-arch@vger.kernel.org, "David S. Miller" , Benjamin Herrenschmidt , Paul Mackerras , Martin Schwidefsky , Heiko Carstens , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" List-Id: linux-arch.vger.kernel.org * Andrew Morton wrote: > > +config DEBUG_PAGEALLOC > > + bool "Debug page memory allocations" > > + depends on DEBUG_KERNEL && ARCH_SUPPORTS_DEBUG_PAGEALLOC > > + depends on !HIBERNATION || !PPC && !SPARC > > + ---help--- > > + Unmap pages from the kernel linear mapping after free_pages(). > > + This results in a large slowdown, but helps to find certain types > > + of memory corruptions. > > + > > I guess this is why it wasn't discovered in my compile testing. > It's quite regrettable that `make allmodconfig' didn't enable the > feature. That's what allmodconfig is for. Hm, i _do_ remember some hibernation magic fix from Rafael, in the area of debugalloc. Many months ago. Rafael, is it supposed to work? If yes, i think we should unblock it. Ingo From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx3.mail.elte.hu ([157.181.1.138]:42728 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933576AbZDCQqS (ORCPT ); Fri, 3 Apr 2009 12:46:18 -0400 Date: Fri, 3 Apr 2009 18:44:50 +0200 From: Ingo Molnar Subject: Re: [PATCH] build fix for generic debug pagealloc Message-ID: <20090403164450.GC3047@elte.hu> References: <20090402163145.GA28728@localhost.localdomain> <20090402094522.b29004c8.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090402094522.b29004c8.akpm@linux-foundation.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Andrew Morton , "Rafael J. Wysocki" Cc: Akinobu Mita , Alexander Beregalov , "linux-next@vger.kernel.org" , LKML , linux-arch@vger.kernel.org, "David S. Miller" , Benjamin Herrenschmidt , Paul Mackerras , Martin Schwidefsky , Heiko Carstens , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" Message-ID: <20090403164450.aKA87jh4-KHqwMtH3PbHhV36tejhWOQebHAZUTk_KO4@z> * Andrew Morton wrote: > > +config DEBUG_PAGEALLOC > > + bool "Debug page memory allocations" > > + depends on DEBUG_KERNEL && ARCH_SUPPORTS_DEBUG_PAGEALLOC > > + depends on !HIBERNATION || !PPC && !SPARC > > + ---help--- > > + Unmap pages from the kernel linear mapping after free_pages(). > > + This results in a large slowdown, but helps to find certain types > > + of memory corruptions. > > + > > I guess this is why it wasn't discovered in my compile testing. > It's quite regrettable that `make allmodconfig' didn't enable the > feature. That's what allmodconfig is for. Hm, i _do_ remember some hibernation magic fix from Rafael, in the area of debugalloc. Many months ago. Rafael, is it supposed to work? If yes, i think we should unblock it. Ingo