/** \ingroup m_task_management
* \brief Changes the CPU affinity of a computation task.
*
* When pinning the given task to the first CPU core of the given host, use
* 0x01 for the mask value. Each bit of the mask value corresponds to each CPU
* core. See taskset(1) on Linux.
*
* \param task a target task
* \param host the host having a multi-core CPU
* \param mask the bit mask of a new CPU affinity setting for the task
*
*
* Usage:
* 0. Define a host with multiple cores.
* \<host id="PM0" power="1E8" core="2"/\>
*
* 1. Pin a given task to the first CPU core of a host.
* MSG_task_set_affinity(task, pm0, 0x01);
*
* 2. Pin a given task to the third CPU core of a host. Turn on the third bit of the mask.
* MSG_task_set_affinity(task, pm0, 0x04); // 0x04 == 100B
*
* 3. Pin a given VM to the first CPU core of a host.
* MSG_vm_set_affinity(vm, pm0, 0x01);
*
* See examples/msg/cloud/multicore.c for more information.
*
*
* Note:
* 1. The current code does not allow an affinity of a task to multiple cores.
* The mask value 0x03 (i.e., a given task will be executed on the first core
* or the second core) is not allowed. The mask value 0x01 or 0x02 works. See
* cpu_cas01.c for details.
*
* 2. It is recommended to first compare simulation results in both the Lazy
* and Full calculation modes (using --cfg=cpu/optim:Full or not). Fix
* cpu_cas01.c if you find wrong results in the Lazy mode.
*
*/
void MSG_task_set_affinity(msg_task_t task, msg_host_t host, unsigned long mask)
{
xbt_assert(task, "Invalid parameter");
xbt_assert(task->simdata, "Invalid parameter");
if (mask == 0) {
/* 0 means clear */
{
/* We need remove_ext() not throwing exception. */
void *ret = xbt_dict_get_or_null_ext(task->simdata->affinity_mask_db, (char *) host, sizeof(msg_host_t));
if (ret != NULL)
xbt_dict_remove_ext(task->simdata->affinity_mask_db, (char *) host, sizeof(host));
}
} else
xbt_dict_set_ext(task->simdata->affinity_mask_db, (char *) host, sizeof(host), (void *) mask, NULL);
/* We set affinity data of this task. If the task is being executed, we
* actually change the affinity setting of the task. Otherwise, this change
* will be applied when the task is executed. */
if (!task->simdata->compute) {
/* task is not yet executed */
XBT_INFO("set affinity(0x%04lx@%s) for %s (not active now)", mask, MSG_host_get_name(host), MSG_task_get_name(task));
return;
}
{
smx_synchro_t compute = task->simdata->compute;
msg_host_t host_now = compute->execution.host; // simix_private.h is necessary
if (host_now != host) {
/* task is not yet executed on this host */
XBT_INFO("set affinity(0x%04lx@%s) for %s (not active now)", mask, MSG_host_get_name(host), MSG_task_get_name(task));
return;
}
/* task is being executed on this host. so change the affinity now */
{
/* check it works. remove me if it works. */
xbt_assert((unsigned long) xbt_dict_get_or_null_ext(task->simdata->affinity_mask_db, (char *) host, sizeof(msg_host_t)) == mask);
}
XBT_INFO("set affinity(0x%04lx@%s) for %s", mask, MSG_host_get_name(host), MSG_task_get_name(task));
simcall_process_execution_set_affinity(task->simdata->compute, host, mask);
}
}
void
xbt_multidict_remove_ext(xbt_dict_t mdict, xbt_dynar_t keys,
xbt_dynar_t lens)
{
volatile xbt_dict_t thislevel;
volatile xbt_dict_t nextlevel = NULL;
volatile int i;
xbt_ex_t e;
unsigned long int thislen;
char *thiskey;
int keys_len = xbt_dynar_length(keys);
xbt_assert(xbt_dynar_length(keys) == xbt_dynar_length(lens));
xbt_assert(xbt_dynar_length(keys),
"Can't remove a zero-long key set in a multidict");
for (i = 0, thislevel = mdict; i < keys_len - 1;
i++, thislevel = nextlevel) {
xbt_dynar_get_cpy(keys, i, &thiskey);
xbt_dynar_get_cpy(lens, i, &thislen);
/* search the dict of next level */
TRY {
nextlevel = xbt_dict_get_ext(thislevel, thiskey, thislen);
}
CATCH(e) {
/* If non-existant entry, nothing to do */
if (e.category == arg_error)
xbt_ex_free(e);
else
RETHROW;
}
}
xbt_dynar_get_cpy(keys, i, &thiskey);
xbt_dynar_get_cpy(lens, i, &thislen);
xbt_dict_remove_ext(thislevel, thiskey, thislen);
}
/** Remove a uintptr_t key from the dict */
XBT_INLINE void xbt_dicti_remove(xbt_dict_t dict, uintptr_t key)
{
xbt_dict_remove_ext(dict, (void *)&key, sizeof key);
}
/**
* \brief Remove data from the dict (null-terminated key)
*
* \param dict the dict
* \param key the key of the data to be removed
*
* Remove the entry associated with the given \a key
*/
XBT_INLINE void xbt_dict_remove(xbt_dict_t dict, const char *key)
{
xbt_dict_remove_ext(dict, key, strlen(key));
}