On Sun, 05 Feb 2012 14:48:38 +0100, Gilad Ben-Yossef <gilad@xxxxxxxxxxxxx> wrote:
Add the on_each_cpu_cond() function that wraps on_each_cpu_mask()
and calculates the cpumask of cpus to IPI by calling a function supplied
as a parameter in order to determine whether to IPI each specific cpu.
The function works around allocation failure of cpumask variable in
CONFIG_CPUMASK_OFFSTACK=y by itereating over cpus sending an IPI a
time via smp_call_function_single().
The function is useful since it allows to seperate the specific
code that decided in each case whether to IPI a specific cpu for
a specific request from the common boilerplate code of handling
creating the mask, handling failures etc.
Signed-off-by: Gilad Ben-Yossef <gilad@xxxxxxxxxxxxx>
Acked-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
CC: Chris Metcalf <cmetcalf@xxxxxxxxxx>
CC: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx>
CC: Frederic Weisbecker <fweisbec@xxxxxxxxx>
CC: Russell King <linux@xxxxxxxxxxxxxxxx>
CC: linux-mm@xxxxxxxxx
CC: Pekka Enberg <penberg@xxxxxxxxxx>
CC: Matt Mackall <mpm@xxxxxxxxxxx>
CC: Sasha Levin <levinsasha928@xxxxxxxxx>
CC: Rik van Riel <riel@xxxxxxxxxx>
CC: Andi Kleen <andi@xxxxxxxxxxxxxx>
CC: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
CC: linux-fsdevel@xxxxxxxxxxxxxxx
CC: Avi Kivity <avi@xxxxxxxxxx>
CC: Michal Nazarewicz <mina86@xxxxxxxxxx>
CC: Kosaki Motohiro <kosaki.motohiro@xxxxxxxxx>
CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
CC: Milton Miller <miltonm@xxxxxxx>
---
include/linux/smp.h | 24 ++++++++++++++++++++
kernel/smp.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 84 insertions(+), 0 deletions(-)
diff --git a/include/linux/smp.h b/include/linux/smp.h
index d0adb78..da4d034 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -153,6 +162,21 @@ static inline int up_smp_call_function(smp_call_func_t func, void *info)
local_irq_enable(); \
} \
} while (0)
+/*
+ * Preemption is disabled here to make sure the
+ * cond_func is called under the same condtions in UP
+ * and SMP.
+ */
+#define on_each_cpu_cond(cond_func, func, info, wait, gfp_flags) \
+ do { \
How about:
void *__info = (info);
as to avoid double execution.
+ preempt_disable(); \
+ if (cond_func(0, info)) { \
+ local_irq_disable(); \
+ (func)(info); \
+ local_irq_enable(); \
+ } \
+ preempt_enable(); \
+ } while (0)
static inline void smp_send_reschedule(int cpu) { }
#define num_booting_cpus() 1
--
Best regards, _ _
.o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o
..o | Computer Science, Michał “mina86” Nazarewicz (o o)
ooo +----<email/xmpp: mpn@xxxxxxxxxx>--------------ooO--(_)--Ooo--
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