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uti: Fix uti thread on the McKernel side blocks others in do_syscall()

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It could block other threads on the same CPU in do_syscall() since it busy-waits after woken up
because it's not allowed to sleep again.
This commit is contained in:
Masamichi Takagi
2017-12-09 15:31:32 +09:00
parent 65667709a8
commit 8c2e20c3aa
1 changed files with 5 additions and 5 deletions
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10
kernel/syscall.c
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@@ -320,11 +320,11 @@ long do_syscall(struct syscall_request *req, int cpu, int pid)
flags = cpu_disable_interrupt_save();
/* Try to sleep until notified */
if (__sync_bool_compare_and_swap(&res.req_thread_status,
IHK_SCD_REQ_THREAD_SPINNING,
IHK_SCD_REQ_THREAD_DESCHEDULED)) {
dkprintf("%s: tid %d waiting for syscall reply...\n",
if (res.req_thread_status == IHK_SCD_REQ_THREAD_DESCHEDULED ||
__sync_bool_compare_and_swap(&res.req_thread_status,
IHK_SCD_REQ_THREAD_SPINNING,
IHK_SCD_REQ_THREAD_DESCHEDULED)) {
kprintf("%s: tid %d waiting for syscall reply...\n",
__FUNCTION__, thread->tid);
waitq_init(&thread->scd_wq);
waitq_prepare_to_wait(&thread->scd_wq, &scd_wq_entry,