lkml.org 
[lkml]   [2012]   [Jan]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[v7 1/8] smp: introduce a generic on_each_cpu_mask function
Date
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>
Reviewed-by: Christoph Lameter <cl@linux.com>
CC: Chris Metcalf <cmetcalf@tilera.com>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Russell King <linux@arm.linux.org.uk>
CC: linux-mm@kvack.org
CC: Pekka Enberg <penberg@kernel.org>
CC: Matt Mackall <mpm@selenic.com>
CC: Rik van Riel <riel@redhat.com>
CC: Andi Kleen <andi@firstfloor.org>
CC: Sasha Levin <levinsasha928@gmail.com>
CC: Mel Gorman <mel@csn.ul.ie>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Alexander Viro <viro@zeniv.linux.org.uk>
CC: linux-fsdevel@vger.kernel.org
CC: Avi Kivity <avi@redhat.com>
CC: Michal Nazarewicz <mina86@mina86.org>
CC: Kosaki Motohiro <kosaki.motohiro@gmail.com>
CC: Milton Miller <miltonm@bga.com>
---
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


\
 
 \ /
  Last update: 2012-01-26 11:05    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site