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do_syscall(): allow schedule for another thread (Intel MPI+OpenMP issue)

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This commit is contained in:
Balazs Gerofi
2016-07-05 18:54:51 +09:00
parent 5c190beb04
commit d135731398
2 changed files with 38 additions and 7 deletions
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43
kernel/syscall.c
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@ -231,16 +231,43 @@ long do_syscall(struct syscall_request *req, int cpu, int pid)
send_syscall(req, cpu, pid);
dkprintf("SC(%d)[%3d] waiting for host.. \n",
ihk_mc_get_processor_id(),
req->number);
dkprintf("%s: syscall num: %d waiting for Linux.. \n",
__FUNCTION__, req->number);
#define STATUS_IN_PROGRESS 0
#define STATUS_COMPLETED 1
#define STATUS_PAGE_FAULT 3
while (res->status != STATUS_COMPLETED) {
while (res->status == STATUS_IN_PROGRESS) {
struct cpu_local_var *v;
int call_schedule = 0;
long runq_irqstate;
cpu_pause();
/* XXX: Intel MPI + Intel OpenMP situation:
* While the MPI helper thread waits in a poll() call the OpenMP master
* thread is iterating through the CPU cores using setaffinity().
* Unless we give a chance to it on this core the two threads seem to
* hang in deadlock. If the new thread would make a system call on this
* core we would be in trouble. For now, allow it, but in the future
* we should have syscall channels for each thread instead of per core,
* or we should multiplex syscall threads in mcexec */
runq_irqstate =
ihk_mc_spinlock_lock(&(get_this_cpu_local_var()->runq_lock));
v = get_this_cpu_local_var();
if (v->flags & CPU_FLAG_NEED_RESCHED) {
call_schedule = 1;
--thread->in_syscall_offload;
}
ihk_mc_spinlock_unlock(&v->runq_lock, runq_irqstate);
if (call_schedule) {
schedule();
++thread->in_syscall_offload;
}
}
if (res->status == STATUS_PAGE_FAULT) {
@ -260,9 +287,8 @@ long do_syscall(struct syscall_request *req, int cpu, int pid)
}
}
dkprintf("SC(%d)[%3d] got host reply: %d \n",
ihk_mc_get_processor_id(),
req->number, res->ret);
dkprintf("%s: syscall num: %d got host reply: %d \n",
__FUNCTION__, req->number, res->ret);
rc = res->ret;
if(islock){
@ -1068,6 +1094,11 @@ do_mmap(const intptr_t addr0, const size_t len0, const int prot,
populated_mapping = 1;
}
/* XXX: Intel MPI 128MB mapping.. */
if (len == 134217728) {
populated_mapping = 0;
}
if (!(prot & PROT_WRITE)) {
error = set_host_vma(addr, len, PROT_READ);
if (error) {