Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759549AbZFWWI4 (ORCPT ); Tue, 23 Jun 2009 18:08:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751888AbZFWWIs (ORCPT ); Tue, 23 Jun 2009 18:08:48 -0400 Received: from mail-yx0-f194.google.com ([209.85.210.194]:62263 "EHLO mail-yx0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759022AbZFWWIr (ORCPT ); Tue, 23 Jun 2009 18:08:47 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:from:date:message-id:subject:to:cc:content-type :content-transfer-encoding; b=rJ+6Esq/APxFL6QmcF4+fTQjOKvxSrI+JE2SUwmA/qH5M2VBfJ1AbX57i8rTp4+o4D EU8B2qixPd9GAZNzIKTA4Gc7dbOxM+yp5Bi+p4Ghir/qDdeak1NUaQ4L0LyUcct+HyIG 3JAOx9I8F6Ord7/0ggJd0wVIzgytB23DAPbaM= MIME-Version: 1.0 From: Mike Frysinger Date: Tue, 23 Jun 2009 18:08:29 -0400 Message-ID: <8bd0f97a0906231508s4c115d3dr2848626bc5a28c5e@mail.gmail.com> Subject: PREEMPT_ACTIVE too low error with all asm-generic headers for some arches To: Ingo Molnar Cc: Linux kernel mailing list Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1747 Lines: 38 after pulling the latest mainline code, Blackfin started hitting a build failure like so: CC arch/blackfin/kernel/asm-offsets.s In file included from include/linux/interrupt.h:12, from include/linux/kernel_stat.h:8, from arch/blackfin/kernel/asm-offsets.c:32: include/linux/hardirq.h:66:2: error: #error PREEMPT_ACTIVE is too low! make[1]: *** [arch/blackfin/kernel/asm-offsets.s] Error 1 this is because we've converted to asm-generic for most of our headers (including hardirq.h). originally we were defining HARDIRQ_BITS ourselves to 8, but then we dropped that in favor of the asm-generic/hardirq.h which setup a default of 8. but then they dropped it in favor of the linux/hardirq.h default handling ... but it sets it to MAX_HARDIRQ_BITS by default which is 10. which pushes Blackfin over the edge and into this build error. if we look at linux/hardirq.h, it makes this claim: * - bit 28 is the PREEMPT_ACTIVE flag if that's true, then why are we letting any arch set this define ? a quick survey shows that half the arches (11) are using 0x10000000 (bit 28) while the other half (10) are using 0x4000000 (bit 26). and then there is the ia64 oddity which uses bit 30. the exact value here shouldnt really matter across arches though should it ? how about adding this to linux/thread_info.h: #ifndef PREEMPT_ACTIVE # ifndef PREEMPT_ACTIVE_BIT # define PREEMPT_ACTIVE_BIT 28 # endif # define PREEMPT_ACTIVE (1 << PREEMPT_ACTIVE_BIT) #endif -mike -- 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/