Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754655AbbKCOjG (ORCPT ); Tue, 3 Nov 2015 09:39:06 -0500 Received: from foss.arm.com ([217.140.101.70]:56017 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751691AbbKCOjD (ORCPT ); Tue, 3 Nov 2015 09:39:03 -0500 Date: Tue, 3 Nov 2015 14:38:59 +0000 From: Catalin Marinas To: Geert Uytterhoeven Cc: Robert Richter , Linux-sh list , Will Deacon , "linux-kernel@vger.kernel.org" , Robert Richter , Tirumalesh Chalamarla , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH] arm64: Increase the max granular size Message-ID: <20151103143858.GI7637@e104818-lin.cambridge.arm.com> References: <1442944788-17254-1-git-send-email-rric@kernel.org> <20151028190948.GJ8899@e104818-lin.cambridge.arm.com> <20151103120504.GF7637@e104818-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151103120504.GF7637@e104818-lin.cambridge.arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2240 Lines: 54 On Tue, Nov 03, 2015 at 12:05:05PM +0000, Catalin Marinas wrote: > On Tue, Nov 03, 2015 at 12:07:06PM +0100, Geert Uytterhoeven wrote: > > On Wed, Oct 28, 2015 at 8:09 PM, Catalin Marinas > > wrote: > > > On Tue, Sep 22, 2015 at 07:59:48PM +0200, Robert Richter wrote: > > >> From: Tirumalesh Chalamarla > > >> > > >> Increase the standard cacheline size to avoid having locks in the same > > >> cacheline. > > >> > > >> Cavium's ThunderX core implements cache lines of 128 byte size. With > > >> current granulare size of 64 bytes (L1_CACHE_SHIFT=6) two locks could > > >> share the same cache line leading a performance degradation. > > >> Increasing the size fixes that. > > >> > > >> Increasing the size has no negative impact to cache invalidation on > > >> systems with a smaller cache line. There is an impact on memory usage, > > >> but that's not too important for arm64 use cases. > > >> > > >> Signed-off-by: Tirumalesh Chalamarla > > >> Signed-off-by: Robert Richter > > > > > > Applied. Thanks. > > > > This patch causes a BUG() on r8a7795/salvator-x, for which support is not > > yet upstream. > > > > My config (attached) uses SLAB. If I switch to SLUB, it works. > > The arm64 defconfig works, even if I switch from SLUB to SLAB. > [...] > > ------------[ cut here ]------------ > > kernel BUG at mm/slab.c:2283! > > Internal error: Oops - BUG: 0 [#1] SMP > [...] > > Call trace: > > [] __kmem_cache_create+0x21c/0x280 > > [] create_boot_cache+0x4c/0x80 > > [] create_kmalloc_cache+0x54/0x88 > > [] create_kmalloc_caches+0x50/0xf4 > > [] kmem_cache_init+0x104/0x118 > > [] start_kernel+0x218/0x33c > > I haven't managed to reproduce this on a Juno kernel. I now managed to reproduce it with your config (slightly adapted to allow Juno). I'll look into it. -- Catalin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/