[PATCH v8 1/8] smp: introduce a generic on_each_cpu_mask function
From: Gilad Ben-Yossef <gilad@benyossef.com>
Date: 2012-02-05 13:44:59
Also in:
linux-fsdevel, lkml
Subsystem:
the rest · Maintainer:
Linus Torvalds
on_each_cpu_mask calls a function on processors specified by cpumask, which may or may not include the local processor. You must not call this function with disabled interrupts or from a hardware interrupt handler or from a bottom half handler. Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com> Acked-by: Peter Zijlstra <redacted> Reviewed-by: Christoph Lameter <redacted> CC: Chris Metcalf <redacted> CC: Frederic Weisbecker <redacted> CC: Russell King <redacted> CC: linux-mm@kvack.org CC: Pekka Enberg <penberg@kernel.org> CC: Matt Mackall <redacted> CC: Rik van Riel <redacted> CC: Andi Kleen <redacted> CC: Sasha Levin <redacted> CC: Mel Gorman <redacted> CC: Andrew Morton <akpm@linux-foundation.org> CC: Alexander Viro <viro@zeniv.linux.org.uk> CC: linux-fsdevel@vger.kernel.org CC: Avi Kivity <redacted> CC: Michal Nazarewicz <redacted> CC: Kosaki Motohiro <redacted> CC: Milton Miller <redacted> --- include/linux/smp.h | 22 ++++++++++++++++++++++ kernel/smp.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 51 insertions(+), 0 deletions(-)
diff --git a/include/linux/smp.h b/include/linux/smp.h
index 8cc38d3..d0adb78 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h@@ -102,6 +102,13 @@ static inline void call_function_init(void) { } int on_each_cpu(smp_call_func_t func, void *info, int wait); /* + * Call a function on processors specified by mask, which might include + * the local one. + */ +void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func, + void *info, bool wait); + +/* * Mark the boot cpu "online" so that it can call console drivers in * printk() and can access its per-cpu storage. */
@@ -132,6 +139,21 @@ static inline int up_smp_call_function(smp_call_func_t func, void *info) local_irq_enable(); \ 0; \ }) +/* + * Note we still need to test the mask even for UP + * because we actually can get an empty mask from + * code that on SMP might call us without the local + * CPU in the mask. + */ +#define on_each_cpu_mask(mask, func, info, wait) \ + do { \ + if (cpumask_test_cpu(0, (mask))) { \ + local_irq_disable(); \ + (func)(info); \ + local_irq_enable(); \ + } \ + } while (0) + static inline void smp_send_reschedule(int cpu) { } #define num_booting_cpus() 1 #define smp_prepare_boot_cpu() do {} while (0)
diff --git a/kernel/smp.c b/kernel/smp.c
index db197d6..a081e6c 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c@@ -701,3 +701,32 @@ int on_each_cpu(void (*func) (void *info), void *info, int wait) return ret; } EXPORT_SYMBOL(on_each_cpu); + +/** + * on_each_cpu_mask(): Run a function on processors specified by + * cpumask, which may include the local processor. + * @mask: The set of cpus to run on (only runs on online subset). + * @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. + * + * If @wait is true, then returns once @func has returned. + * + * You must not call this function with disabled interrupts or + * from a hardware interrupt handler or from a bottom half handler. + */ +void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func, + void *info, bool wait) +{ + int cpu = get_cpu(); + + smp_call_function_many(mask, func, info, wait); + if (cpumask_test_cpu(cpu, mask)) { + local_irq_disable(); + func(info); + local_irq_enable(); + } + put_cpu(); +} +EXPORT_SYMBOL(on_each_cpu_mask);
--
1.7.0.4
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