From e48c15b796d412ede883bb2ef7779b2a142f7962 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 29 Jun 2020 17:21:32 -0700 Subject: smp: Add source and destination CPUs to __call_single_data This commit adds a destination CPU to __call_single_data, and is inspired by an earlier commit by Peter Zijlstra. This version adds #ifdef to permit use by 32-bit systems and supplying the destination CPU for all smp_call_function*() requests, not just smp_call_function_single(). If need be, 32-bit systems could be accommodated by shrinking the flags field to 16 bits (the atomic_t variant is currently unused) and by providing only eight bits for CPU on such systems. It is not clear that the addition of the fields to __call_single_node are really needed. [ paulmck: Apply Boqun Feng feedback on 32-bit builds. ] Link: https://lore.kernel.org/lkml/20200615164048.GC2531@hirez.programming.kicks-ass.net/ Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Sebastian Andrzej Siewior Cc: Frederic Weisbecker Signed-off-by: Paul E. McKenney --- kernel/smp.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'kernel/smp.c') diff --git a/kernel/smp.c b/kernel/smp.c index d0ae8eb6bf8b..865a876f83ce 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -375,6 +375,9 @@ int smp_call_function_single(int cpu, smp_call_func_t func, void *info, csd->func = func; csd->info = info; +#ifdef CONFIG_64BIT + csd->dst = cpu; +#endif err = generic_exec_single(cpu, csd); @@ -540,6 +543,9 @@ static void smp_call_function_many_cond(const struct cpumask *mask, csd->flags |= CSD_TYPE_SYNC; csd->func = func; csd->info = info; +#ifdef CONFIG_64BIT + csd->dst = cpu; +#endif if (llist_add(&csd->llist, &per_cpu(call_single_queue, cpu))) __cpumask_set_cpu(cpu, cfd->cpumask_ipi); } -- cgit v1.2.3