Messages in this thread Patch in this message | | | Date | Fri, 14 Feb 2003 07:49:16 -0500 (EST) | From | Zwane Mwaikambo <> | Subject | Re: [PATCH][2.5][7/14] smp_call_function_on_cpu - PPC64 |
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One liner to fix num_cpus == 0 on SMP kernel w/ UP box
Index: linux-2.5.60/arch/ppc64/kernel/smp.c =================================================================== RCS file: /build/cvsroot/linux-2.5.60/arch/ppc64/kernel/smp.c,v retrieving revision 1.1.1.1 diff -u -r1.1.1.1 smp.c --- linux-2.5.60/arch/ppc64/kernel/smp.c 10 Feb 2003 22:15:14 -0000 1.1.1.1 +++ linux-2.5.60/arch/ppc64/kernel/smp.c 14 Feb 2003 12:23:03 -0000 @@ -452,29 +452,34 @@ #define SMP_CALL_TIMEOUT (1UL << (30 + 3)) /* - * This function sends a 'generic call function' IPI to all other CPUs - * in the system. + * smp_call_function_on_cpu - Runs func on all processors in the mask * - * [SUMMARY] Run a function on all other CPUs. - * <func> The function to run. This must be fast and non-blocking. - * <info> An arbitrary pointer to pass to the function. - * <nonatomic> currently unused. - * <wait> If true, wait (atomically) until function has completed on other CPUs. - * [RETURNS] 0 on success, else a negative status code. Does not return until - * remote CPUs are nearly ready to execute <<func>> or are or have executed. + * @func: The function to run. This must be fast and non-blocking. + * @info: An arbitrary pointer to pass to the function. + * @wait: If true, wait (atomically) until function has completed on other CPUs. + * @mask The bitmask of CPUs to call the function + * + * Returns 0 on success, else a negative status code. Does not return until + * remote CPUs are nearly ready to execute func or have executed it. * * You must not call this function with disabled interrupts or from a * hardware interrupt handler or from a bottom half handler. */ -int smp_call_function (void (*func) (void *info), void *info, int nonatomic, - int wait) + +int smp_call_function_on_cpu (void (*func) (void *info), void *info, int wait, + unsigned long mask) { struct call_data_struct data; - int ret = -1, cpus = num_online_cpus()-1; + int ret, cpu, i, num_cpus; unsigned long timeout; - if (!cpus) + cpu = get_cpu(); + mask &= ~(1UL << cpu); + num_cpus = hweight64(mask); + if (num_cpus == 0) { + put_cpu_no_resched(); return 0; + } data.func = func; data.info = info; @@ -487,11 +492,18 @@ call_data = &data; wmb(); /* Send a message to all other CPUs and wait for them to respond */ - smp_message_pass(MSG_ALL_BUT_SELF, PPC_MSG_CALL_FUNCTION, 0, 0); + if (mask == (cpu_online_map & ~(1UL << cpu))) { + smp_message_pass(MSG_ALL_BUT_SELF, PPC_MSG_CALL_FUNCTION, 0, 0); + } else { + for (i = 0; i < NR_CPUS; i++) { + if (cpu_online(i) && ((1UL << i) & mask)) + smp_message_pass(i, PPC_MSG_CALL_FUNCTION, 0, 0); + } + } /* Wait for response */ timeout = SMP_CALL_TIMEOUT; - while (atomic_read(&data.started) != cpus) { + while (atomic_read(&data.started) != num_cpus) { HMT_low(); if (--timeout == 0) { #ifdef CONFIG_DEBUG_KERNEL @@ -499,15 +511,16 @@ debugger(0); #endif printk("smp_call_function on cpu %d: other cpus not " - "responding (%d)\n", smp_processor_id(), + "responding (%d)\n", cpu, atomic_read(&data.started)); + ret = -EIO; goto out; } } if (wait) { timeout = SMP_CALL_TIMEOUT; - while (atomic_read(&data.finished) != cpus) { + while (atomic_read(&data.finished) != num_cpus) { HMT_low(); if (--timeout == 0) { #ifdef CONFIG_DEBUG_KERNEL @@ -516,20 +529,27 @@ #endif printk("smp_call_function on cpu %d: other " "cpus not finishing (%d/%d)\n", - smp_processor_id(), + cpu, atomic_read(&data.finished), atomic_read(&data.started)); + ret = -EIO; goto out; } } } ret = 0; - out: HMT_medium(); spin_unlock(&call_lock); + put_cpu_no_resched(); return ret; +} + +int smp_call_function (void (*func) (void *info), void *info, int nonatomic, + int wait) +{ + return smp_call_function_on_cpu(func, info, wait, cpu_online_map); } void smp_call_function_interrupt(void) - 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/
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