From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 3 May 2007 01:57:29 -0700 From: Andrew Morton Subject: Re: 2.6.22 -mm merge plans: slub Message-Id: <20070503015729.7496edff.akpm@linux-foundation.org> In-Reply-To: References: <20070430162007.ad46e153.akpm@linux-foundation.org> <20070501125559.9ab42896.akpm@linux-foundation.org> <20070503011515.0d89082b.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Hugh Dickins Cc: Christoph Lameter , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Thu, 3 May 2007 09:46:32 +0100 (BST) Hugh Dickins wrote: > On Thu, 3 May 2007, Andrew Morton wrote: > > On Wed, 2 May 2007 10:25:47 -0700 (PDT) Christoph Lameter wrote: > > > > > +config ARCH_USES_SLAB_PAGE_STRUCT > > > + bool > > > + default y > > > + depends on SPLIT_PTLOCK_CPUS <= NR_CPUS > > > + > > > > That all seems to work as intended. > > > > However with NR_CPUS=8 SPLIT_PTLOCK_CPUS=4, enabling SLUB=y crashes the > > machine early in boot. > > I thought that if that worked as intended, you wouldn't even > get the chance to choose SLUB=y? That was how it was working > for me (but I realize I didn't try more than make oldconfig). Right. This can be tested on x86 without a cross-compiler: ARCH=powerpc make mrproper ARCH=powerpc make fooconfig > > > > Too early for netconsole, no serial console. Wedges up uselessly with > > CONFIG_XMON=n, does mysterious repeated uncontrollable exceptions with > > CONFIG_XMON=y. This is all fairly typical for a powerpc/G5 crash :( > > > > However I was able to glimpse some stuff as it flew past. Crash started in > > flush_old_exec and ended in pgtable_free_tlb -> kmem_cache_free. I don't know > > how to do better than that I'm afraid, unless I'm to hunt down a PCIE serial > > card, perhaps. > > That sounds like what happens when SLUB's pagestruct use meets > SPLIT_PTLOCK's pagestruct use. Does your .config really show > CONFIG_SLUB=y together with CONFIG_ARCH_USES_SLAB_PAGE_STRUCT=y? > Nope. g5:/usr/src/25> grep SLUB .config CONFIG_SLUB=y g5:/usr/src/25> grep SLAB .config # CONFIG_SLAB is not set g5:/usr/src/25> grep CPUS .config CONFIG_NR_CPUS=8 # CONFIG_CPUSETS is not set # CONFIG_IRQ_ALL_CPUS is not set CONFIG_SPLIT_PTLOCK_CPUS=4 It's in http://userweb.kernel.org/~akpm/config-g5.txt -- 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