Messages in this thread Patch in this message | | | From | Frederic Weisbecker <> | Subject | [PATCH 11/11] smp: Enhance and precise the role & requirements of __smp_call_function_single() | Date | Sat, 8 Feb 2014 17:18:40 +0100 |
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Be more specific on the description of __smp_call_function_single(). It's actually not that much about just being able to embed a csd in an object.
Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> --- kernel/smp.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/kernel/smp.c b/kernel/smp.c index b767631..24cb936 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -238,13 +238,20 @@ int smp_call_function_single(int cpu, smp_call_func_t func, void *info, EXPORT_SYMBOL(smp_call_function_single); /** - * __smp_call_function_single(): Run a function on a specific CPU + * __smp_call_function_single(): Run an asynchronous function on a + * specific CPU. * @cpu: The CPU to run on. * @csd: Pre-allocated and setup data structure * - * Like smp_call_function_single(), but allow caller to pass in a - * pre-allocated data structure. Useful for embedding @data inside - * other structures, for instance. + * Like smp_call_function_single(), but the call is asynchonous and + * can thus be done from contexts with disabled interrupts. + * + * The caller passes his own pre-allocated data structure + * (ie: embedded in an object) and is responsible for synchronizing it + * such that the IPIs performed on the @csd are strictly serialized. + * + * NOTE: Be careful, there is unfortunately no current debugging facility to + * validate the correctness of this serialization. */ int __smp_call_function_single(int cpu, struct call_single_data *csd) { -- 1.8.3.1
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