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cpumask: convert RCU implementations

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Impact: use new cpumask API.

rcu_ctrlblk contains a cpumask, and it's highly optimized so I don't want
a cpumask_var_t (ie. a pointer) for the CONFIG_CPUMASK_OFFSTACK case.  It
could use a dangling bitmap, and be allocated in __rcu_init to save memory,
but for the moment we use a bitmap.

(Eventually 'struct cpumask' will be undefined for CONFIG_CPUMASK_OFFSTACK,
so we use a bitmap here to show we really mean it).

We remove on-stack cpumasks, using cpumask_var_t for
rcu_torture_shuffle_tasks() and for_each_cpu_and in force_quiescent_state().

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Rusty Russell
2009-01-01 10:12:26 +10:30
parent d036e67b40
commit bd232f97b3
4 changed files with 44 additions and 38 deletions
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27
kernel/rcutorture.c
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@@ -868,49 +868,52 @@ static int rcu_idle_cpu; /* Force all torture tasks off this CPU */
*/
static void rcu_torture_shuffle_tasks(void)
{
cpumask_t tmp_mask;
cpumask_var_t tmp_mask;
int i;
cpus_setall(tmp_mask);
if (!alloc_cpumask_var(&tmp_mask, GFP_KERNEL))
BUG();
cpumask_setall(tmp_mask);
get_online_cpus();
/* No point in shuffling if there is only one online CPU (ex: UP) */
if (num_online_cpus() == 1) {
put_online_cpus();
return;
}
if (num_online_cpus() == 1)
goto out;
if (rcu_idle_cpu != -1)
cpu_clear(rcu_idle_cpu, tmp_mask);
cpumask_clear_cpu(rcu_idle_cpu, tmp_mask);
set_cpus_allowed_ptr(current, &tmp_mask);
set_cpus_allowed_ptr(current, tmp_mask);
if (reader_tasks) {
for (i = 0; i < nrealreaders; i++)
if (reader_tasks[i])
set_cpus_allowed_ptr(reader_tasks[i],
&tmp_mask);
tmp_mask);
}
if (fakewriter_tasks) {
for (i = 0; i < nfakewriters; i++)
if (fakewriter_tasks[i])
set_cpus_allowed_ptr(fakewriter_tasks[i],
&tmp_mask);
tmp_mask);
}
if (writer_task)
set_cpus_allowed_ptr(writer_task, &tmp_mask);
set_cpus_allowed_ptr(writer_task, tmp_mask);
if (stats_task)
set_cpus_allowed_ptr(stats_task, &tmp_mask);
set_cpus_allowed_ptr(stats_task, tmp_mask);
if (rcu_idle_cpu == -1)
rcu_idle_cpu = num_online_cpus() - 1;
else
rcu_idle_cpu--;
out:
put_online_cpus();
free_cpumask_var(tmp_mask);
}
/* Shuffle tasks across CPUs, with the intent of allowing each CPU in the