Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753090Ab3EMQly (ORCPT ); Mon, 13 May 2013 12:41:54 -0400 Received: from webmail.solarflare.com ([12.187.104.25]:24986 "EHLO webmail.solarflare.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751297Ab3EMQlw (ORCPT ); Mon, 13 May 2013 12:41:52 -0400 Message-ID: <1368463307.3305.23.camel@bwh-desktop.uk.solarflarecom.com> Subject: Re: Build regressions/improvements in v3.10-rc1 (s390) From: Ben Hutchings To: Heiko Carstens CC: Geert Uytterhoeven , , Stuart Hodgson , Linux Kernel Development , , Date: Mon, 13 May 2013 17:41:47 +0100 In-Reply-To: <20130513074159.GA4290@osiris> References: <20130513074159.GA4290@osiris> Organization: Solarflare Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3 (3.2.3-3.fc16) Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-Originating-IP: [10.17.20.137] X-TM-AS-Product-Ver: SMEX-10.0.0.1412-7.000.1014-19862.005 X-TM-AS-Result: No--16.728700-0.000000-31 X-TM-AS-User-Approved-Sender: Yes X-TM-AS-User-Blocked-Sender: No Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1775 Lines: 36 On Mon, 2013-05-13 at 09:41 +0200, Heiko Carstens wrote: > On Sun, May 12, 2013 at 10:50:45PM +0200, Geert Uytterhoeven wrote: > > On Sun, 12 May 2013, Geert Uytterhoeven wrote: > > > However, the full list of errors isn't that unmanageable, so I'm following > > > up with a digested list... > > > > drivers/net/ethernet/sfc/efx.c:646:3: error: call to '__compiletime_assert_648' declared with attribute error: BUILD_BUG_ON failed: sizeof(struct efx_rx_page_state) + EFX_PAGE_IP_ALIGN + EFX_RX_USR_BUF_SIZE > PAGE_SIZE / 2: 2 errors in 2 logs > > v3.10-rc1/s390x/s390-allyesconfig v3.10-rc1/s390x/s390-allmodconfig > > that seems to a BUILD_BUG_ON that only triggers on s390, because we have > L1_CACHE_BYTES defined with 256 bytes... which seems to be more than any > other architecture has. > There was a different network driver that had a similar BUILD_BUG_ON, but > it got removed. > > Right, it was the igb driver: > http://comments.gmane.org/gmane.linux.network/261378 The critical value here is EFX_RX_USR_BUF_SIZE. The hardware constrains it to be a multiple of 32, but for performance reasons it also ought to be a multiple of the cache line size(s). In our internal development branch it has already been reduced to 1792, which is a multiple of 256 and should satisfy the BUILD_BUG_ON check. I'll post a patch shortly. Ben. -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked. -- 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/