From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: [PATCH 02/15] arm: __NR_syscalls fix Date: Fri, 11 Apr 2014 11:33:51 +0100 Message-ID: <20140411103351.GJ16119@n2100.arm.linux.org.uk> References: <1397211951-20549-1-git-send-email-miklos@szeredi.hu> <1397211951-20549-3-git-send-email-miklos@szeredi.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1397211951-20549-3-git-send-email-miklos@szeredi.hu> Sender: linux-kernel-owner@vger.kernel.org To: Miklos Szeredi Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Miklos Szeredi List-Id: linux-arch.vger.kernel.org On Fri, Apr 11, 2014 at 12:25:38PM +0200, Miklos Szeredi wrote: > From: Miklos Szeredi > > Signed-off-by: Miklos Szeredi > Cc: Russell King > --- This has me wondering... (a) what you think it fixes (b) whether you tried to build-test this The ARM instruction set supports 8-bit immediate constants with an even power of two shift. 384 fits that (0x180), 382 does not (0x17e), and in your following patch, 383 definitely doesn't (0x17f). Having this constant larger than necessary does not cause any problem for the syscall table: we explicitly pad it with calls to sys_ni_syscall to make up the difference. -- FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly improving, and getting towards what was expected from it. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gw-1.arm.linux.org.uk ([78.32.30.217]:57991 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1757379AbaDKKe2 (ORCPT ); Fri, 11 Apr 2014 06:34:28 -0400 Date: Fri, 11 Apr 2014 11:33:51 +0100 From: Russell King - ARM Linux Subject: Re: [PATCH 02/15] arm: __NR_syscalls fix Message-ID: <20140411103351.GJ16119@n2100.arm.linux.org.uk> References: <1397211951-20549-1-git-send-email-miklos@szeredi.hu> <1397211951-20549-3-git-send-email-miklos@szeredi.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1397211951-20549-3-git-send-email-miklos@szeredi.hu> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Miklos Szeredi Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Miklos Szeredi Message-ID: <20140411103351.LjBOOGxFiE97wRFzN-fuYHq14-_77LqhkErvjbNsEOo@z> On Fri, Apr 11, 2014 at 12:25:38PM +0200, Miklos Szeredi wrote: > From: Miklos Szeredi > > Signed-off-by: Miklos Szeredi > Cc: Russell King > --- This has me wondering... (a) what you think it fixes (b) whether you tried to build-test this The ARM instruction set supports 8-bit immediate constants with an even power of two shift. 384 fits that (0x180), 382 does not (0x17e), and in your following patch, 383 definitely doesn't (0x17f). Having this constant larger than necessary does not cause any problem for the syscall table: we explicitly pad it with calls to sys_ni_syscall to make up the difference. -- FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly improving, and getting towards what was expected from it.