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[kernel][thread] gcc 10.2 warning fix

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In a previous patch, on architectures where SMP is disabled,
thread_pinned_cpu() will always return a negative number. GCC 10.2
is somewhat more aggressive about negative shift values so it wasn't
detecting that the second path of an if statement is never taken.

Solution is to cache the pinned cpu value and use it for both the
test and the operation.
This commit is contained in:
Travis Geiselbrecht
2020-10-09 01:25:03 -07:00
parent 961ef679cf
commit ed7e3571c2
1 changed files with 7 additions and 4 deletions
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11
kernel/thread.c
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@@ -101,10 +101,11 @@ static void wakeup_cpu_for_thread(thread_t *t)
{
/* Wake up the core to which this thread is pinned
* or wake up all if thread is unpinned */
if (thread_pinned_cpu(t) < 0)
int pinned_cpu = thread_pinned_cpu(t);
if (pinned_cpu < 0)
mp_reschedule(MP_CPU_ALL_BUT_LOCAL, 0);
else
mp_reschedule(1U << thread_pinned_cpu(t), 0);
mp_reschedule(1U << pinned_cpu, 0);
}
void init_thread_struct(thread_t *t, const char *name) {
@@ -1180,10 +1181,12 @@ int wait_queue_wake_all(wait_queue_t *wait, bool reschedule, status_t wait_queue
t->state = THREAD_READY;
t->wait_queue_block_ret = wait_queue_error;
t->blocking_wait_queue = NULL;
if (thread_pinned_cpu(t) < 0) {
int pinned_cpu = thread_pinned_cpu(t);
if (pinned_cpu < 0) {
/* assumes MP_CPU_ALL_BUT_LOCAL is defined as all bits on */
cpu_mask = MP_CPU_ALL_BUT_LOCAL;
} else {
cpu_mask |= (1U << thread_pinned_cpu(t));
cpu_mask |= (1U << pinned_cpu);
}
insert_in_run_queue_head(t);
ret++;