From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262689AbTDEWIk (for ); Sat, 5 Apr 2003 17:08:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262692AbTDEWIk (for ); Sat, 5 Apr 2003 17:08:40 -0500 Received: from siaab1ab.compuserve.com ([149.174.40.2]:39558 "EHLO siaab1ab.compuserve.com") by vger.kernel.org with ESMTP id S262689AbTDEWIg (for ); Sat, 5 Apr 2003 17:08:36 -0500 Date: Sat, 5 Apr 2003 17:17:33 -0500 From: Chuck Ebbert <76306.1226@compuserve.com> Subject: Re: [PATCH] New cpu macro and i386 cleanup To: Robert Love Cc: linux-kernel Message-ID: <200304051719_MC3-1-3328-B238@compuserve.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Robert Love wrote: > On a glance, it looked like at least some of them were. Looks like do_rdmsr is not disabling preempt. This should fix it (compiled not tested.) diff -u --exclude-from=/home/me/.exclude -r linux-2.5.66-ref/arch/i386/kernel/cpuid.c linux-2.5.66-uni/arch/i386/kernel/cpuid.c --- linux-2.5.66-ref/arch/i386/kernel/cpuid.c Sat Mar 29 09:16:32 2003 +++ linux-2.5.66-uni/arch/i386/kernel/cpuid.c Fri Apr 4 18:45:19 2003 @ -56,7 +56,7 @ { struct cpuid_command *cmd = (struct cpuid_command *) cmd_block; - if ( cmd->cpu == smp_processor_id() ) + if ( is_current_cpu(cmd->cpu) ) cpuid(cmd->reg, &cmd->data[0], &cmd->data[1], &cmd->data[2], &cmd->data[3]); } @ -65,7 +65,7 @ struct cpuid_command cmd; preempt_disable(); - if ( cpu == smp_processor_id() ) { + if ( is_current_cpu(cpu) ) { cpuid(reg, &data[0], &data[1], &data[2], &data[3]); } else { cmd.cpu = cpu; diff -u --exclude-from=/home/me/.exclude -r linux-2.5.66-ref/arch/i386/kernel/msr.c linux-2.5.66-uni/arch/i386/kernel/msr.c --- linux-2.5.66-ref/arch/i386/kernel/msr.c Sat Mar 29 09:16:32 2003 +++ linux-2.5.66-uni/arch/i386/kernel/msr.c Sat Apr 5 16:18:29 2003 @ -100,7 +100,7 @ { struct msr_command *cmd = (struct msr_command *) cmd_block; - if ( cmd->cpu == smp_processor_id() ) + if ( is_current_cpu(cmd->cpu) ) cmd->err = wrmsr_eio(cmd->reg, cmd->data[0], cmd->data[1]); } @ -108,7 +108,7 @ { struct msr_command *cmd = (struct msr_command *) cmd_block; - if ( cmd->cpu == smp_processor_id() ) + if ( is_current_cpu(cmd->cpu) ) cmd->err = rdmsr_eio(cmd->reg, &cmd->data[0], &cmd->data[1]); } @ -118,29 +118,31 @ int ret; preempt_disable(); - if ( cpu == smp_processor_id() ) { + if ( is_current_cpu(cpu) ) ret = wrmsr_eio(reg, eax, edx); - preempt_enable(); - return ret; - } else { + else { cmd.cpu = cpu; cmd.reg = reg; cmd.data[0] = eax; cmd.data[1] = edx; smp_call_function(msr_smp_wrmsr, &cmd, 1, 1); - preempt_enable(); - return cmd.err; + + ret = cmd.err; } + preempt_enable(); + return ret; } static inline int do_rdmsr(int cpu, u32 reg, u32 *eax, u32 *edx) { struct msr_command cmd; + int ret; - if ( cpu == smp_processor_id() ) { - return rdmsr_eio(reg, eax, edx); - } else { + preempt_disable(); + if ( is_current_cpu(cpu) ) + ret = rdmsr_eio(reg, eax, edx); + else { cmd.cpu = cpu; cmd.reg = reg; @ -148,9 +150,10 @ *eax = cmd.data[0]; *edx = cmd.data[1]; - - return cmd.err; + ret = cmd.err; } + preempt_enable(); + return ret; } #else /* ! CONFIG_SMP */ diff -u --exclude-from=/home/me/.exclude -r linux-2.5.66-ref/include/linux/smp.h linux-2.5.66-uni/include/linux/smp.h --- linux-2.5.66-ref/include/linux/smp.h Tue Mar 4 22:29:21 2003 +++ linux-2.5.66-uni/include/linux/smp.h Sat Apr 5 16:33:09 2003 @ -134,6 +134,12 @ } #endif /* !SMP */ + /* is_current_cpu() is not preempt-safe. + * Use 'cpu == get_cpu()' and then put_cpu() + * if preempt not already disabled. + */ +#define is_current_cpu(cpu) ((cpu) == smp_processor_id()) + #define get_cpu() ({ preempt_disable(); smp_processor_id(); }) #define put_cpu() preempt_enable() #define put_cpu_no_resched() preempt_enable_no_resched() diff -u --exclude-from=/home/me/.exclude -r linux-2.5.66-ref/include/linux/threads.h linux-2.5.66-uni/include/linux/threads.h --- linux-2.5.66-ref/include/linux/threads.h Tue Mar 4 22:28:55 2003 +++ linux-2.5.66-uni/include/linux/threads.h Sat Mar 29 11:01:55 2003 @ -20,6 +20,9 @ #define NR_CPUS 1 #endif +#define FIRST_CPU 0 +#define LAST_CPU (NR_CPUS - 1) + #define MIN_THREADS_LEFT_FOR_ROOT 4 /* -- Chuck I am not a number!